Commercial Gardening MARKET CHRYSANTHEMUMS i. Le Peyron. 2. Freda Bedford. 3. Elsie Fulton. 4. Mrs. F. MacNeice (Half natural size) ffi SB COMMERCIAL GARDENING A PRACTICAL & SCIENTIFIC TREATISE FOR MARKET GARDENERS MARKET GROWERS FRUIT FLOWER & VEGE- ** TABLE GROWERS NURSERYMEN ETC. 00 tMany 'Practical Specialists under the Editorship of JOHN WEATHERS Author of "A Practical Guide to Garden Plants" "French Market Gardening" "The Bulb Book" &c. 41 ' m In Four Volumes: Fully Illustrated VOLUME I (3D v (J! THE GRESHAM PUBLISHING COMPANY (JO 34-35 Southampton Street Strand London ~ ~ - " PREFACE The very title of this work at once distinguishes it from all other treatises on Horticulture, and at the same time strikes a note indicating its predominant features. The work is "commercial" in every sense of the term, because it deals with gardening from the point of view of the man who grows plants not so much for pleasure as for profit. It is also " gardening " in the best sense of the word, as the cultural methods of the best market growers are detailed. Commercial Gardening, indeed, is intended as a work not only for the bookshelves, but for the hands of all those who are engaged, or intend to become engaged, in Horticulture for Profit, and who are desirous of growing those crops of fruits, flowers, or vegetables likely to yield the most remunerative results. In considering gardening from what may be called a pounds, shillings, and pence point of view, it is essential to take note chiefly of those crops that can be grown in the open air or under glass, and are likely to yield a profit, large or small, upon their cultivation. It does not at all follow that what may be justly regarded as the loveliest and most charming flowers, the most decorative plants, or the finest-flavoured fruits or vege- tables, are necessarily those that" will yield the handsomest profits when cultivated on a large scale. Unfortunately the reverse is often the case, and enormous numbers of various plants are grown, not because they happen to be the very finest representatives of their class, but simply because they find a more ready sale in the markets than their choicer brethren. This is easily explained on the ground that those who grow produce for sale, and those who buy it, belong to quite different classes of the community. The market buyer usually is not a trained horticulturist, and he will only invest in produce that has already made a name for itself, and is therefore not likely to remain long on his hands. If he ventures to invest in produce which he has never seen before, or knows but little about, he finds that when he recommends it to his customers they leave VI Preface it severely alone evidently under the impression that he is trying to push unduly the sale of what he considers to be a useless drug on the market. Many excellent plants have met this fate, and it has taken years before others have become sufficiently well-known to florists, greengrocers, and street sellers to make their cultivation at all profitable. Sometimes, however, a new kind or variety will jump into popular favour at once, and the commercial gardener, who is regularly in touch with the markets and is being constantly influenced by their atmosphere and traditions, proceeds at once to propagate and cultivate the new favourite in sufficiently large quantities to meet the demand. In this way some of the older favourites are gradually displaced by the newer ones, and it is only when one comes to compare the kinds or varieties of plants or flowers that were sold in quantities twenty, thirty, or fifty years ago with those sold at the present day, that one realizes what enormous changes have taken place. Not only have new races superseded old ones, but the cultural methods of commercial gardeners have also undergone remarkable changes. Cleaner and more economic methods of cultivation also prevail to-day, and gar- deners who have to make a living out of the growth of plants have in many cases come to recognize the vast importance of the scientific aspects of their calling. In these days the grower who would erect glasshouses with small panes of glass and an enormous quantity of timber would be regarded as insane. The importance of light and fresh air is now so well understood, that the main object in view is to secure as much of each, especially during the winter months, as is possible. The market gardener has perhaps more to learn in this respect than the market grower. In many instances he practises the old and erroneous farming system of cramming and crowding his fruit trees and bushes to- gether in such a way that in a few years they become a mass of diseased and distorted vegetation, yielding very poor, if any, profit. It is one of the most difficult things to make some of the old school of market gardeners and farmers realize that the great bulk of the dry weight of any plant fruit, flower, or vegetable is obtained from the carbon of the atmosphere under the influence of sunlight. They simply will not believe it because they cannot see it. It is ever present to the minda of such that to give any plant a fair amount of space and air and light, according to its nature, would be " wasting ground ", as they term it. The natural corollary to this lack of knowledge is the thought that the greater the number of plants put into a given area of ground, the larger and better Preface VII the crops likely to be got out of it one of the most pernicious and dangerous doctrines for any commercial gardener to play with. In this work on Commercial Gardening the best and cleanest methods of cultivation are those recommended, simply because they happen to be the most economical. But no false economy is preached, and it may be cheaper, even for the man with a small capital, to make a fair start by thoroughly cultivating his ground to a depth of 3 ft., at a cost of 8 to 12 per ac., than to fritter away his substance for a lifetime and never go deeper than six inches or a foot from the surface. The cultivator who is now foolish enough to think that the methods employed by his ancestors in the old non-competitive days are quite good enough for him, is making a sad mistake in these speedy days of keen competition. The modern grower is affected by the changes brought about by science and fashion, and he must adjust his methods and vary his crops according to prevailing circumstances. Perhaps it only remains to be said that the information given in this work has been supplied by men most of whom are, or have been, actually engaged in growing crops of various kinds for profit, and are regarded as skilful cultivators and good business men. The Editor takes this opportunity of thanking them for their kind assistance, and in doing so would also like to express his indebtedness to many other com- mercial gardeners who prefer to handle the spade rather than the pen for many hints and much information given in regard to various matters. Among the principal contributors the following may be mentioned, with the initials used to mark their contributions throughout the work. A. A. ARTHUR AMOS, Downing College, Cambridge. A. J. B. A. J. BRIDGES, Nurseryman. C. E. CARL ENGELMANN, Nurseryman and Carnation Specialist. C. T. D. CHARLES T. DRUERY, President, British Fern Society. E. H. J. E. H. JENKINS, Nurseryman and Horticultural Writer. F. V. T. Professor F. V. THEOBALD, M.A., Zoologist to the S.E. Agricultural College, Wye; Author of Insect and Allied Pests of Orchard, Bush, and Hothouse Fruits. F. W. M. Sir FREDERICK W. MOORE, M.A., F.L.S., Glasnevin. G. G. GEORGE GORDON, V.M.H., Editor of the Gardeners' Magazine. G. M. GEORGE MASSEE, F.L.S., &c. ; Author of Diseases of Plants. Vlll Preface J. B. R. JAMES B. RIDING, Nurseryman and Horticultural Writer. J. E. H, JOSEPH ERNEST HILL, J.P., Fern Specialist and Nurseryman. J. F. JOHN FRASER, F.L.S., late Editor, Gardening World. J. M. JOHN MAY, late Market Grower and Cyclamen Specialist. J. M. H. J. M. HODGE, Blairgowrie. J. U. JAMES UDALE, Chief Horticultural Instructor, Worcestershire County Council. J. W. JOHN WEATHERS, formerly a Market Grower, Author of A Practical Guide to Garden Plants, French Market Gardening, Lecturer on Horticulture, &c. P. A. C. PERCY A. CRAGG, Market Grower. W. M. B. WILFRID M. BEAR, Grape and Tomato Grower. W. G. L. WILLIAM G. LOBJOIT, J.P., Market Gardener and Fruit Grower, Vice- Chairman of the Market Gardeners', Farmers', and Nurserymen's Association. W. T. WILLIAM TRUELOVE, Nursery Propagator. CONTENTS VOLUME I SECTION L GENERAL ASPECTS OF COMMERCIAL GARDENING Page Introductory The Seed Trade The Bulb Trade The Hardy-plant Trade The Nursery Trade Market Gardening and Market Growing The Florist Trade Tree and Shrub Trade Japanese Gardening 1 SECTION II. THE SCIENCE OF PLANT GROWING 1. SIMPLE AND COMPLEX CELL LIFE. Simple Cell Life - 20 2. STRUCTURE OF THE HIGHER PLANTS. The Growth of a Cell Changes in Cell Walls Various Forms of Cells Plant Tissues Uses of Different Cells - - 22 3. PLANTS OF DISTINCTIVE CHARACTER. Plants with Chlorophyll Plants without Chlorophyll Desert Plants Clammy -leaved Plants Insectivorous Plants Climbing Plants - 26 4. THE ROOT AND ITS WORK. The Primary Root Importance of Primary and Fibrous Roots Relation of Soil to Roots Water and Air Roots Tuberous Roots Work of the Roots The Food absorbed by Roots Contractile Roots - - 29 5. THE STEM AND ITS FUNCTIONS. The Seedling Stem The Growth and Thickening of the Stem The Cambium Dicotyledonous and Monocotyledonous Stems Bulbs, Corms, Tubers, and Rhizomes - - 35 6. LEAVES AND THEIR WORK. Seed Leaves and True Leaves Structure and Contents of a Leaf Work of a Leaf Forms of Leaves and their Clothing Arrangement of Leaves Modified Leaves The Fall of the Leaf - - 42 7. MOVEMENTS OF WATER AND FOOD PRODUCTS IN PLANTS. Root Pressure Water of Transpiration Transport of Food Materials Water Plants Sap in Winter Bleeding - - 52 Contents 8. MODES OF GROWTH AND VEGETATIVE EEPRODUCTION. Mono- podial and Sympodial Stems Forms of Inflorescence Flower Buds and Pruning Propagation by Roots Propagation by Stems Propagation by Leaves - 55 9. THE FLOWER AND ITS FUNCTIONS. The Parts of a Flower Pollination and Fertilization Sexual Reproduction Cross- breeding and Hybridization Various Forms of Fruit Seeds Germination - - 60 SECTION III. METHODS OF PROPAGATION Seeds Vitality of Seeds Seed Sowing Cuttings Woody Cuttings Leaf Cuttings Ringing Root Cuttings Layering Runners Suckers Offsets Bulbils Division of the Rootstock Bud- ding Grafting Whip Grafting Cleft and Rind Grafting Saddle Grafting Side Grafting Herbaceous Grafting Root Grafting Inarching or Grafting by Approach Bottle Grafting 71 SECTION IV. THE SCIENCE OF THE SOIL 1. INTRODUCTORY - 89 2. CLASSIFICATION OF SOILS. Sand Clay Loam Chalk Lime Peat Humus Advantages of Humus - - 91 3. MECHANICAL ANALYSIS OF SOILS - 96 4. How SOILS HAVE BEEN MADE. Water Frost Heat Wind Vegetation - - 98 5. CULTURAL OPERATIONS. Ploughing Digging Double Digging Trenching Ridging Up Raking and Harrowing Rolling Hoeing - - 101 6. THE BEST TIME TO WORK THE SOIL - - 107 7. PLANT FOODS IN THE SOIL AND AIR - - 108 8. How TO EXTRACT PLANT FOODS FROM THE SOIL - 112 9. WATER IN THE SOIL. How Moisture is Lost Loss of Water through the Leaves Movement of Water in the Soil Water Lost by Weeds The Upward Movement of Moisture in Soils: Capillary Attraction Conserving the Moisture in Soil: The Use of Hoeing and Mulching - - 116 10. LIVING ORGANISMS IN THE SOIL. Nitrification Soil Inoculation Deriitrification - - 125 11. STERILIZING SOILS. Burning and Steaming the Soil - - 130 12. ELECTRIFYING THE SOIL - - 131 13. SOIL ANALYSIS. Chemical Analysis Lime Carbonate Phos- phates Potash Iron Calcium Carbonate Humus Magnesia 132 Contents xi SECTION V. MANURES AND MANURING Page 1. INTRODUCTORY. Misleading Experiments The Object of Manuring 137 2. KINDS OF MANURES - - 145 3. COMPLETE MANURES. Farmyard Manure or Dung Storing Farm- yard Manure Value of Farmyard Manure A Warning Green Manuring Leaves as a "Green Crop" Roots as a Manure Guano Fish Guano Seaweed Soot Blood Manures Night Soil and Poudrette Rape Cake and Rape Dust Malt Dust or Kiln Dust Wool and Shoddy Hair, Feathers, Skin, Leather Waste, Greaves - - 146 4. NITROGENOUS MANURES. Nitrate of Lime Nitrate of Soda or Chili Saltpetre Nitrate of Potash Sulphate of Ammonia Nitrolim or Calcium Cyanamide - - 154 1 5. PHOSPHATIC MANURES. Bones Superphosphate Basic Slag Wood Ashes, &c. Limphos - - 156 .6. POTASH MANURES. Kainit Muriate of Potash Sulphate of Potash - - 158 7. CALCAREOUS MANURES. Chalk Marl Gas Lime Gypsum (Cal- cium Sulphate) - 159 1 8. MISCELLANEOUS MANURES. Magnesium Salts Iron Salt, or Chloride of Sodium - - 161 .9. VALUATION OF MANURES - - 162 .10. MIXING MANURES - - 164 SECTION VI INSECT PESTS Introductory Greenhouse Pests Fumigating Vaporizing Cyaniding Outdoor Pests Seeking the Cause Life-history and Habits of Garden Pests Methods of Prevention Chrysalides Table of Insect Pests - 166 SECTION VII GARDEN FRIENDS Ladybirds The Devil's Coach Horse The Violet Ground Beetle The Tiger Beetle Frogs, Toads, and Lizards Hawkflies Ichneu- mon Flies Lacewing Flies Ear-shelled Slug Spiders The Weasel Centipedes - 197 SECTION VIIL FUNGOID DISEASES Introductory Fungoid Diseases of Fruit Trees Fungoid Diseases of Vegetables '- - - 203 xii Contents SECTION IX. FUNGICIDES AND INSECTICIDES Page Ammoniacal Copper Fungicide or Cupram Arsenate of Lead (Sugar of Lead) Bordeaux Mixture Carbon Bisulphide Caustic Wash or Winter Wash Copper Sulphate (Bluestone, Blue Vitriol, Copperas) Copper Sulphate and Washing Soda (Burgundy Mixture) Eau Celeste Hellebore Powder Hydrocyanic Acid Gas Iron Sulphate (Green Vitriol, Ferrous Sulphate) Paraffin Emulsion (Petroleum, Kerosene, &c.) Paraffin Jelly Paris Green (Emerald Green, French Green, Mitis Green) Pearl Ash (Potassium Carbonate) Pyrethrum (Dalmatian Insect Powder, Persian Insect Powder) Quassia Chips Quicklime Sodium Cyanide Soft Soap (Whale-oil Soap, Train-oil Soap, Fish-oil Soap, Potash Soap) Sulphide of Potassium or Liver of Sulphur Tobacco Winter Washes of Lime and Sulphur Woburn Wash - - 211 SECTION X. GLASSHOUSE BUILDING General Greenhouses on Rails - - - 218 SECTION XL HEATING APPARATUS Boilers Sectional Boilers Setting Boilers Principles of Hot -water Circulation Quantity of Piping Required Fuel - - 231 LIST OF PLATES VOLUME I Page MARKET CHRYSANTHEMUMS (in colour) - - -Frontispiece 1. Le Peyron. 2. Freda Bedford. 3. Elsie Fulton. 4. Mrs. F. MacNeice. BULB FARMING AT WISBECH, CAMBRIDGESHIRE ... 4 JAPANESE GARDENING - 16 PERPETUAL CARNATIONS (in colour) - 28 1. Carola. 2. White Perfection. 3. Victory. 4. Enchantress. DUTCH AND ENGLISH TULIP FARMS - 40 DUTCH AND ENGLISH HYACINTH FARMS - 56 SEED WAREHOUSES - 72 SALPIGLOSSIS (in colour) - - 100 A MIDDLESEX MARKET GARDEN AT DAFFODIL TIME; A CITY OF GLASSHOUSES AT WALTHAM CROSS, NEAR LONDON - - 130 FLORAL ART - 160 PERENNIAL PHLOXES (in colour) - - 198 1. Crepuscule. 2. Coquelicot. 3. Tapis Blanc. GENERAL VIEW OF MR. H. 0. LARSEN'S NURSERY, WALTHAM ABBEY; VIEW OF MODERN GLASSHOUSES AT MESSRS. E. COBLEY & Co.'s NURSERY, CHESHUNT - - 218 MODERN GLASSHOUSES - - 222 INTERIOR VIEW OF MODERN GREENHOUSE - 226 GREENHOUSES ON KAILS, SHOWING MOVABLE ENDS AND KAIL BETWEEN; INTERIOR OF GREENHOUSE ON RAILS, SHOWING CROP OF NARCISSUS 230 TREES AND SHRUBS PACKED FOR EXPORT TO AMERICA AT MR. J. SMITH'S NURSERY, DARLEY DALE, DERBYSHIRE; FORCED LILAC PLANTS GROWN IN POTS FOR EXHIBITION - 236 xiii SECTION I General Aspects of Commercial Gardening During the past fifty or sixty years horticulture has sprung into a prominent position as one of the leading industries of the United King- dom. Horticulture, unlike its twin sister agriculture, is not represented in Parliament, and the only legislative notice taken of it has been to make its disciples pay rates and taxes on their skill and industry. When we have a Minister of Horticulture, as the French and Belgians have, then perhaps the horticultural trade will receive as much consideration as agriculture does in connection with the rating of the land, and more importance will be attached to it as a national industry. Horticulture, as distinct from agriculture, has to deal with the cultiva- tion of all kinds of plants and flowers, fruits and vegetables, both in the open air and under glass. Besides our native hardy fruits, flowers, and vegetables, the horticulturist also has to grow exotics from all parts of the world from the tropics, subtropics, and temperate regions, from the mountains and valleys, and from all kinds of soils and situations. To bring these to perfection necessitates considerable skill, besides great expense. The horticulturist has found out that the rather antediluvian methods of the agriculturist would be of little use to him. He must mix his soils and composts in various ways to suit particular crops, and he must regulate the temperature by means of glasshouses and frames and hot-water apparatus if he is to succeed. This necessitates outlay in other directions, and the timber, glass, and iron trades benefit by his enterprise, as well as many others that supply horticultural sundries. Indeed it is almost impossible to describe the intricate details of horti- cultural practice, and it must suffice to say that they are such as would astonish the average agriculturist. Although both farmer and gardener have to practise the same principles of cultivation for outdoor crops, the gardener, even with these, will devote far more attention to detail, and will spend an amount of money every year in cultivation that the farmer would consider exorbitant or extravagant. The farmer leaves VOL. I. 1 J Commercial Gardening a good deal to nature; but the gardener, and especially the commercial gardener, cannot afford to leave his various crops altogether exposed to the mercies of a somewhat fickle climate. He prepares his soil to a greater depth, and feeds it more richly with manure than does the farmer; and he also pays greater attention to cultural details. In addition, he must gather his crops, not for cattle, but for human consumption, just when they are ready, and he must pack them in such a way that they will readily attract buyers in the markets. At one time, indeed, the market gardener was little better than a farmer in his cultural and business methods, and he sent produce to market in a very slipshod manner. The stress of competition at home and the importations from abroad, however, have completely changed the methods of the modern market grower. He has found out by experience that the finer, better, and cleaner his produce, and the better it is packed or displayed, the higher the prices and the quicker the sales. He has learnt much in these respects from the way produce from the Colonies and from the Continent is placed on the markets, and he realizes that good stuff badly displayed will often fetch miserably low prices. This work on commercial gardening deals principally with those classes of plants that are grown in large quantities either in the open air or under glass for sale in the London and provincial markets, and also those that are grown by nurserymen and hardy-plantsmen in fairly large numbers to meet the demands of their customers who do not patronize the markets. There are, indeed, so many ramifications of the horticultural trade, each intimately associated with the other, and depen- dent on each other, that it may be well to say a few words about each to show how one is linked up with the other. The Seed Trade. This branch of commercial gardening has assumed immense proportions of late years. In various parts of the kingdom firms have established trial grounds where their seeds are not only saved, but where new varieties likely to have a ready sale are also tested and proved before being placed upon the market. This work necessitates great care and cultural skill; and expensive machinery, driven by steam or the more modern electricity, is used to cleanse the seeds from impurities of every sort. Large warehouses have to be built to accommodate the stocks, not only of home-saved seed, but also of that imported from sunnier climes than our own. To give some idea as to the trade done in seeds it is only necessary to state that one firm alone sells each year about 50,000 bus. of culinary Peas: 51,000 bus. of root-crop seeds; 6500 bus. of Beans; 41 tons of seeds of the various Cabbage crops; 1300 bus. of Radish seeds; 25 tons of Beet seed: 1400 bus. of Spinach seed; 10 tons of Onion seed; 17 tons of Carrot seed; 220 bus. of Parsley seed; 10 tons of Parsnip seed; 15 tons of Sweet Pea seed; 14 tons of Nasturtium (Tropaeolum) seed; and 3 tons of Mignonette seed. Seeds of annuals, biennials, and perennials of all kinds are sold in large quantities year after year, and are retailed in packets costing from Id. upwards. General Aspects of Commercial Gardening 3 The Bulb Trade. Although a large proportion of the bulb trade is undoubtedly Continental, there has been a magnificent effort on the part of British and Irish growers to produce large quantities at home. While such bulbs as Hyacinths and Tulips and Daffodils have been for genera- tions a staple industry of the Dutch growers, signs are not wanting that equally good bulbs can be grown in several places in the United Kingdom. With the exception perhaps of Hyacinths, other bulbs of a hardy nature might be grown more extensively. In the Channel Islands and the Scilly Islands, in parts of Ireland and England, Tulip and Daffodil bulbs are now grown on a large scale and of the finest quality, but the methods of British growers in calling attention to their stocks are far inferior to those adopted by the Dutch. The latter band themselves together for mutual trade benefit, and make a point of encouraging visits to their bulb farms every season. The trade practically commences in the spring, when Dutch growers book orders from the visiting growers, and deliver the goods as early in autumn as possible. During the summer months from May to August their travellers invade the British Islands and America, and push the bulb trade so well that they take home fine fat orders for early autumn delivery. From September to December the trade is brisk amongst retailers, while the market grower has already boxed his bulbs of Tulips, Daffodils, Hyacinths, Crocuses, Snowdrops, &c., to secure an early Christmas and Easter trade. Tulips, Daffodils, Hyacinths, and Crocuses are abundant from Christmas to Easter; while Lilium longiflorum is now practically in season through- out the year. Gladioli of the Colvillei and nanus sections are also useful for spring work, while the Brenchleyensis, Childsi, and Nanceianus sections come in for late summer or early autumn work. Apart from bulbs proper, such tuberous-rooted plants as Arum Lilies are in great request from Christmas to Easter and Whitsuntide, the chief trade being done in the blooms or spathes. Ixias, Freesias, Snowdrops, German, Spanish, and English Irises, Tuberoses, Montbretias, Solomon's Seal, Crown Imperials, Herbaceous Paeonies, Eucharis, Dahlias, &c., are amongst other bulbous and tuberous plants that find a ready sale throughout the year at their own particular season, for the cut-flower trade. Each group is dealt with in its proper place in Vol. II of this work. Amongst retail nurserymen and bulb merchants other bulbous and tuberous plants dealt in, as well as those mentioned, are Begonias, Dicentras, Gloxinias, Hippeastrum, Leucojum, Chionodoxa, Scilla, Alstroe- meria, Brodiaea, Brevoortia, Galtonia, Hsemanthus, Ranunculus, Winter Aconite (Eranthis), Calochortus, Camassia, Colchicum, Erythronium or Dog's Tooth Violet, Eremurus, Incarvillea, Ixiolirion, Lycoris, Milla or Triieleia, Muscari or Grape Hyacinth, Ornithogalum or Star of Bethlehem, and many others, including the Water Lilies or Nymphaeas which have become popular of late years. Most of these are practically hardy, and the trade in them is confined to nurserymen and hardy-plantsmen who Commercial Gardening deal with the owners of private establishments. Each genus is dealt with amongst the "Plants and Flowers" in Vol. II. The Hardy -plant Trade. Of late years the trade in hardy plants has assumed almost gigantic proportions. Not only are large quantities of hardy herbaceous perennials actually sent to the various markets for sale packed in various ways and sold as "roots", but a still larger trade is done through the post, by means of exhibitions, and by advertising in the papers. Owing to the cost of erecting glasshouses, the cost of fuel, and other items of expense many private people have discarded glass altogether, or the newer generation has not taken a fancy to it owing to the trouble and expense. To such, the hardy herbaceous perennials, and hardy annuals and biennials, naturally appeal with great force. There is no need to have glasshouses of any description to grow these plants, and even a cold frame can be dispensed with; and yet a mag- nificent display may be secured by a judicious selection of plants that will flourish in the open air in most parts of the kingdom without any artificial protection. This being the case, it is not to be wondered at that a large trade has sprung up in these plants, and something like three or four thousand different species are now dealt in by various growers, some of whom hold valuable stocks of the best-selling kinds, while others cater for a select group of plant connoisseurs and botanical establishments. The grower of hardy plants, as a rule, does not go to market, and his methods of business .are quite different from those of the market grower. He relies very largely for his sales upon his catalogues (which are often works of art), upon exhibitions in all parts of the kingdom, and upon judicious advertising, very much in the same way as the seedsman and bulb merchant do. Thousands of people now interested in gardening will gladly pay a reasonable price for a plant in which they are interested, and they will visit flower shows and exhibitions in the hope of seeing something new, or something they would like to have in their collection. The hardy-plantsmen, therefore, who make a practice of displaying their specialities at the various exhibitions up and down the country stand an excellent chance of making new customers if they exhibit really choice and well-grown stuff', and set it up with all the art of window dressing. The old style of jumbling plants up "anyhow" at an exhibition is no longer sufficient. The exhibitor adopts various devices, and when space permits he makes miniature herbaceous borders, rock gardens, water gardens, and he arranges his goods in such an artistic way that the would-be purchaser is at once captivated, and longs to produce a similar floral picture in his own garden. This naturally leads not only to the sale of plants, but also to the engagement of landscapemen, who know how to turn a piece of waste land into a smiling flower garden. Many firms now make a speciality of laying out gardens artistically and naturally, and although some amateurs try their untrained hands at the business, they generally have to call in the aid of the man who knows his plants and their nature and uses by everyday intercourse and experience. A FIELD OF NARCISSUS A FIELD OF SPANISH IRISES BULB FARMING AT WISBECH, CAMBRIDGESHIRE (Mr. J. W. Cross) General Aspects of Commercial Gardening 5 While exhibiting is one of the best means of doing business for the grower of hardy plants, it must be remembered that it entails a large expense. The mere carriage of the plants by rail or road, apart from hotel and other expenses, often means a substantial sum, the recovery of which will depend largely upon the weather and upon the class of visitors to the exhibition. Some growers of hardy plants rarely exhibit, but rely upon the post and advertisements to dispose of their goods. Hundreds of thousands of young plants and cuttings are sent through the post to the most remote parts of the kingdom, to fill orders that have come to hand as the result of reading an advertisement. Some, indeed, spend from 50 to 100 a week during the season in advertising alone, and this will give some idea as to the volume of the trade. Not only are hardy plants disposed of rapidly in this way, but also half-hardy and tender plants during the season, as may be seen by referring to the advertise- ment columns of the trade and amateur papers. From what has been said it will be gathered that the great trade in hardy plants of all kinds, and in seeds and cuttings, as well as in bulbous and tuberous plants, is largely done by means of judicious advertising. The plant grower not only supports the newspapers, but he also places large orders with the printers for thousands of catalogues that are issued broadcast, but not without considerable expense. Some of the larger firms issue as many as eighty thousand beautifully prepared catalogues every year, weighing in the aggregate from 90 to 100 tons; while smaller men print and distribute catalogues according to their means. In all cases, however, the General Post Office, the printers, and newspaper pro- prietors have had the first pick at the seedsman's or hardy-plantsman's purse, and he is left to settle his account with a more or less fickle public. The Nursery Trade. This branch of commercial gardening has extensive ramifications all over the kingdom. All kinds of plants, fruits, flowers, and vegetables are grown for sale in the open or under glass, and thousands of gardeners are employed to propagate and grow them. There are many special branches in the nursery trade. Thus some make a speciality of Roses, some of fruit trees, some of ornamental trees and shrubs, some of stove and greenhouse plants, some of Ferns, some of Orchids, some chiefly of forest trees, some of hardy herbaceous perennials and alpines, and rock and water plants and perhaps not one of these nurserymen ever sends a plant to a market. The nurseryman is quite distinct in his methods of trading from the market grower and the market gardener. He makes a speciality of various classes of plants, and has every nook and corner of the globe ransacked by horticultural travellers, who are on the lookout for any new plant likely to attract attention. Besides pushing his trade by means of travellers, advertisements, and catalogues, the nurseryman proper also relies largely upon exhibitions. These are held regularly not only in London, where the finest class of trade is done, but in almost every town of any importance in the kingdom, 6 Commercial Gardening at different periods of the year. In some cases exhibitions on the Conti- nent are also visited, and in this way some firms have worked up a large international or cosmopolitan trade. These exhibitions naturally cost much money, not only for transport, but for the maintenance and lodging of the necessary staff; and it is essential to reap a good harvest in the way of orders to enable one to pay the expenses and leave a balance on the right side. Market Gardening- and Market Growing-. The business of the market gardener and the market grower is different in a technical sense. The market gardener proper, as a rule, grows fruits and vegetables on a large scale in the same way that the farmer grows corn and root crops. If he indulges in glass at all it is a few frames at the most to raise early supplies of seedlings to put out at the first favourable opportunity in spring; or he may use bell glasses or cloches to protect his early cauli- flowers and marrows, much in the same way as the French cultivators do. Market gardening has been a great industry in the Thames valley for generations, and notwithstanding the operations of the builder, and the enormous growth of the London suburbs, there is still a large area around the metropolis devoted to market gardening. Of course the market gardener is being pushed farther and farther out, but with improved methods of transit, and better roads, the man twenty or thirty miles from London is probably in as good a position as his predecessor was fifty or sixty years ago, when only a dozen miles from Covent Garden. Old market-garden districts like Deptford, Fulham, and Chelsea have been wiped out by the builder, and buildings and roads now take the place of cabbages, rhubarb, fruit trees and bushes that not so many years ago made those neighbourhoods truly rural. This pressure from the centre has naturally driven the market gardener farthei out, and such places as Feltham, Ashford, Sipson, Staines, West Drayton, Harmonds- worth, Bedfont, Shepperton, Stanwell, and Cranford, in Middlesex, are becoming covered with fruit and vegetable gardens. Kent, Surrey, and Essex are being invaded in much the same way, and there seems to be a tendency to increase the acreage under these crops. From Mortlake to Richmond and Petersham, on the south side of the Thames, market gardens still exist, but it will probably not be for very long. Chiswick, on the north bank, still contains some of its ancient market gardens, and these extend to Brentford, Isle worth, Heston, and Hounslow; but in these famous market-garden areas the builder is rapidly covering the ground with bricks and mortar. The vale of Evesham in Worcestershire has become famous as a centre, not only for the market culture of fruits and vegetables, but also as the first place in the British Islands where " inten- sive cultivation " as practised around Paris was established. For particulars of this system the reader is referred to Vol. IV. While the market gardener is seeking fresh fields for his labours, the market grower who brings his crops to maturity under glass has come very much to the front during the past thirty or forty years. General Aspects of Commercial Gardening 7 There are now enormous areas of glasshouses erected all round the metropolis, but more especially to the north in such places as Edmonton, Ponder's End, Enfield, Waltham Cross; in the north-west round Finchley, Whetstone, and Potter's Bar; and to the west at Isle worth, Feltham, Hillingdon, Uxbridge, Sipson, and West Drayton. In other parts of the kingdom, notably Worthing and the Channel Islands (principally Guern- sey), large areas of ground have also been covered with glass. This has naturally led to the development of other businesses, such as the timber trade and the iron trade. Glasshouses are now built on quite different principles from what they were twenty or thirty years ago, and growers are at last beginning to realize the great value of light to their crops, and to appreciate structures that will allow the maximum amount of sunshine through the glass. Less wood and more glass is now the rule. In the iron trade, enormous quantities of material are used for the manufacture of boilers and pipes; while the manufacturers of paint, putty, and other materials also do a brisk trade with market growers. To these must be added the various gas companies and colliery merchants, who provide thousands of tons of coke or anthracite coal to feed the furnaces attached to the glasshouses. The crops grown under glass are naturally of a quite different nature from those grown in the open air. They require greater care and skill in cultivation, and frequent changes are made in accordance with the alterations in fashion or the fluctuations of the market. Cucumbers, Tomatoes, Grapes, Ferns, Palms, Aspidistras, Chrysanthemums, bedding plants, Melons, Peaches, constitute some of the chief crops grown exten- sively under glass, and they are all dealt with in their proper places in Vols. II, III, and IV of this work. Such outdoor crops, however, as Cab- bages, Lettuces, Radishes, Mint, Rhubarb, Sea Kale, Dwarf and Runner o ' * ' Beans, Marrows, &c., are also now grown extensively under glass by many to supply the early markets and thus pander to the fashion of having everything in as early as possible before its natural period. Notwithstanding the numbers of market growers who now send pro- duce to the London and provincial markets, it is astonishing to see the enormous quantities of fruits, flowers, and vegetables that are imported from the Continent and the Colonies. The increased speed of trains and steamboats now renders it possible to bring supplies to market that a few years ago would have been considered impossible. The introduction of the refrigerating system on trains and steamboats has still further aided the introduction of colonial and foreign produce to British markets one of the surest signs that they are the most lucrative in the world. If they were not, supplies would soon cease, and trade would flow to the markets where the " biggest penny " was to be secured. The Florist Trade. There is scarcely a town of any pretensions in the British Islands that does not boast of at least one florist's shop. In large provincial towns there are many, and in the metropolis itself and its suburbs there are many hundreds. The floral trade has developed 8 Commercial Gardening enormously during the past twenty or thirty years, and the florists' shops are the main outlets for most of the decorative plants and flowers grown by market nurserymen. It would indeed be a poor prospect for the latter if the business of the florist was interfered with or hampered by increased burdens of taxation. The more florists there are in the country the better for the growers of plants and flowers. Incidentally, the florists' shops are a sign of the general prosperity of the people, because their trade may be regarded more in the light of a luxury of art and taste than as an actual necessity. The business carried on by the florist is of a varied character. He is an adept at the making of bouquets of all kinds for weddings or Court functions. Wreaths, crosses, anchors, pillars, cushions, and numerous other floral emblems for the departed also come within his sphere of influence, in addition to which he sells masses of cut flowers in a natural state, as well as decorative pot plants, little shrubs, &c. And where the florist happens to be also a nurseryman, he undertakes landscape work and jobbing. In all these operations his raw material consists of plants and flowers of all descriptions, hardy and tender, and he is ever on the watch to invent new designs, or to arrange his flowers, &c., in such a way that they will attract attention and excite admiration. Some of the leading- London florists have made their names famous by the taste and original ideas they display not only in the making of wreaths, bouquets, &c., but in the artistic way they decorate or furnish banquet halls, theatres, reception rooms, &c. All important public functions in any town or city lead to business being done by the florist; and he who displays the greatest taste, originality, and industry is the one most likely to be patronized. The florist and furnishing trade indeed cannot be learned in a day. Many an excellent grower of plants and flowers used in floral decorations would make but a sorry job of it if he had to arrange his own procce for a public function. It takes years to become an expert florist, and in some branches of the trade, such as the making of wreaths, bouquets, &c., women stand as good a chance as men, if not a better. The operator must be not only skilful and quick in " mounting " the flowers on various kinds of wires and "foundations", but must display considerable taste in the arrangement of the individual flowers, and of their effects upon one another. It is quite possible for the choicest flowers to be as easily spoiled in effect in the hands of an incompetent florist as it is for good viands to be spoiled in the hands of an incompetent cook. A skilled florist will produce a finer effect with a few inexpensive blossoms than an unskilled one will with a cartload of choice material, just as some women can dress charmingly at little expense while others will look dowdy in the finest materials and jewellery. There is no end to learning in the florist's business, and the fashion of to-day may be out of date to-morrow. Great and wonderful changes have taken place within the past thirty years in the way flowers are General Aspects of Commercial Gardening 9 arranged. Formerly bouquets were made in a round, flat, and dumpy style, having row after row of flowers arranged in circles round the centrepiece. The whole arrangement was flat and formal, and was finished up with a collar of fancy paper. This heavy style of bouquet has long since disappeared, and a lighter and more graceful arrange- ment has taken its place. This has been brought about by the introduc- tion of different kinds of flowers and trailing plants, and the different methods of sending them to market. Twenty and thirty years ago nearly all flowers were cut with very short stalks, so that the florist, to produce any effect at all, was obliged to mount many of them on wires to raise them above their neighbours. In these days, however, florists insist on having flowers with the natural stems as long as possible, so that a variety of designs is more easily obtained. The grower who would now send short-stemmed Roses or Carnations to market would find his wares on his hands when the market closed. With some classes of flowers, such as Camellias, Tuberoses, and Eucharis, it is impossible to supply long stems to the individual flowers, and what they lack in this respect must be made up by the florist in other ways. Amongst the most important of the florist's accessories are wires of various kinds, and moss for the foundations of wreaths, crosses, anchors, and other emblems. The stiffish wires used for mounting flowers are known as stubs, and are of varying length and thickness, according to the purposes for which they are required. Special wires are also used for the mounting of Roses, Camellias, Tuberoses, &c., and it takes some considerable time for the beginner to find out, not only the proper stubs and wires to be used for certain purposes, but to acquire that manual dexterity which distinguishes the expert from the tyro. The foundations of various sizes and shapes are made of strong galvan- ized wire by the horticultural sundriesman, so that they will not bend or twist when in use. These foundations are covered with soft moss tied on with string or wire, and into the moss the flowers, mounted on wires or stubs, are stuck. Years ago, before the use of stubs became common, flowers were tied down to the moss foundations, and the general effect was flat and unrelieved. Nowadays, however, flowers can be arranged in various styles some flat, some slightly raised, some bunched boldly in certain places and forming the piece de resistance of the whole work all of which variations depend upon the artistic perceptions of the operator. Owing to the more frequent interchange between British and Continental florists now than formerly, constant changes are taking place, and one notices how largely the ideas of the Continental florists are being assimi- lated by their British brethren, and vice versa. Popular Florists Flowers. Perhaps the florist attaches more impor- tance to the colour than to the form of the flowers he uses in his business. As a rule, flowers with clear and distinct shades of colour are most appre- ciated; while those with confused tones or lacking in brilliancy are prac- tically useless. A colour that will not show up well at nighttime under io Commercial Gardening gas-light or electric light is of little use, because a good deal of the florist's art is seen under these conditions. White Flowers. Taking the colours all in all, white is undoubtedly the most popular, and enormous quantities of white-flowered plants must be grown to meet the ever-increasing demand. Amongst the most important plants used for a supply of white flowers to the florists the following may be mentioned: Lily of the Valley; Lilium longiflorum (Harrisi); Lilium speciosum or lancifolium album,; JSucharis grandiflora ; Camellias; Tuberoses (Polianthes); Freesia refracta alba; Tulip, La Reine; Roman Hyacinths; Florists' Hyacinth, La Grandesse; Gladiolus Colvillei, The Bride; Stephanotis; Lapageria alba; Bouvardia; Rose, Niphetos; Gar- denias; Carnations; Phlox; Chrysanthemums; Dahlias; China Asters; Stocks; Azaleas; Pink, Mrs. Simkins and Her Majesty; Zonal Pelargonium Hermione (double); Gloxinias; Snowdrops; Paper-white Narcissus; Star of Bethlehem (Ornithogalum); Odontoglossum crispum; Christmas Roses (Helleborus niger); Arum Lilies (Richardia); Hoteia (Spircea) japonica; Gypsophila paniculata and G. elegans; Achillea, The Pearl; Sweet Peas; Spanish Iris; Florentine Iris; Paeonies; Plialcenopsis grandiflora, amabilis, RieTnstedtiana, &c. Apart from white, flowers of all other colours are utilized in great abundance, and the principal kinds used may be noted as follows: Roses of all kinds; Violets, double and single; Carnations Perpetual and Border varieties; Daffodils and Narcissi; Tulips; Hyacinths; Gladiolus; Dahlias; Chrysanthemums ; Phlox ; Forget-me-nots ; Zonal Pelargonium Raspail, double scarlet; Orchids such as Cattleyas, Dendrobiums, Oncidiurns, Odonto- glossums, Laelias, and Phalsenopsis. Trailers. For " shower " bouquets, festoons, and table decorations it is useful to have certain plants with slender trailing stems and foliage that will not soon wither. Amongst the best plants for this purpose are Asparagus Sprengeri, A. plumosus, and A. plumosus nanus (all known as Asparagus "Ferns"), A. medeoloides (or Myrsiphyllum asparagoides) far better known to florists as " Smilax ". A great trade is done in the trails of these plants, and some growers make a speciality of their culture. Foliage. For backing up many flowers used in wreaths, crosses, bou- quets, &c., it is sometimes essential to have foliage that will throw the blossoms into greater relief, and a large number of plants are grown for this purpose. Until the various kinds of Asparagus were introduced, the fronds of the Maidenhair Fern were used in enormous quantities for almost everything. Of late years, however, the foliage of other plants has been utilized, and florists now stock in the proper season the leaves of such plants as: Crotons, Maples, Holly-leaved Barberry (Berberis Aquifolium), Copper Beech, Ivy, Copper Hazel, Purple Plum, Scarlet Oak, Galax aphylla, large-leaved Myrtle, &c., to which must be added for winter work sprays of Mistletoe and of Holly in leaf and berry. There is still a great trade done in what is known as "French Fern" (Asplenium adiantum- niqrum\ the fronds of which are sold in bunches. The old conventional General Aspects of Commercial Gardening u ideas, however, are gradually vanishing, and it is now customary to use the natural foliage of any flower that may be used in floral work. Thus violet leaves are most appropriately used with violet blossoms, as holly leaves are the most suitable adjuncts to the scarlet berries. Indeed there is no end to the methods employed by the modern florist to produce a charming effect; and the plant and flower grower who will introduce a new plant, or suggest a novel idea, is looked upon as a floral friend. Tree and Shrub Trade. This is a very important branch of com- mercial horticulture, and one about which the general public knows but little. It may be divided into two principal groups, viz.: (1) that dealing with forest trees, and (2) ornamental flowering trees and shrubs. In regard to forest trees it is astonishing what an enormous number of young plants are raised every year in different parts of England, Ireland, and Scotland. Those who are under the impression that British forestry is a dead or dying industry have no idea as to the amount of business done in forest trees, and it is a pity that the Chancellor of the Exchequer and the officials of the Board of Agriculture are not better informed as to what is being done in this respect. There are hundreds of capable men, who could not only plant all the waste land in the United Kingdom in a comparatively short time, but who could produce millions of young forest trees annually to fill the gaps that might occur. And yet Mr. Lloyd George, when introducing his famous 1909 Budget, said in reference to the scheme of afforestation : " I am also told that we cannot command the services in this country of a sufficient number of skilled foresters to direct planting. I am advised, and, personally, I am disposed to accept that counsel as the advice of prudence, that the greater haste in this matter will mean the less speed, and that to rush into planting on a huge scale without first of all making the necessary experiments, organizing a trained body of foresters, and taking all other essential steps to ensure success when you advance, would be to court disaster which might dis- courage all future attempts." It would be interesting to know whose advice the Chancellor of the Exchequer relied upon when he stated that " we cannot command the services in this country of a sufficient number of skilled foresters to direct planting", but there was no doubt about its misleading character. We wonder what kind of men they are who raise and plant thousands of forest trees annually? Have they no knowledge of the trees they raise, and are they not skilled in planting and growing them? The Chancellor's some- what misleading statement is calculated to injure the reputation of a large number of skilful and hard-working men who earn a living by carry- ing out the very duties which the Chancellor was advised were not and could not at present be performed. These men, skilled in the raising, planting, and cultivation of forest trees, may not, of course, be able to pass an examination in Greek and Latin, or in Conic Sections and Trigonometry, nor have they had the disadvantage of a "public-school training"; but they know their business, and if the Chancellor of the Exchequer will only 12 Commercial Gardening start the Government Afforestation Scheme at once, he will find plenty of skilful foresters who will see that the preparation and planting of the 17,000,000 acres of waste ground in the United Kingdom are carried out properly. Raising Forest Trees. The simplest method of raising these is from seeds. These are collected when ripe in autumn and carefully stored until the spring. In some cases, however, like the Willow, Poplar, Elm, in which the seed ripens early, sowing may take place during the summer months. The seed land is prepared by ploughing or digging, and harrow- ing and raking, until it is brought to a fine tilth. Drills are then drawn at regular distances apart, varying from 3 in. to 12 in. according to the kind of seed that is sown, each kind being covered with three or four times its own depth of soil, and afterwards lightly rolled. In some cases seeds are sown broadcast over beds about 5 ft. wide, but generally speaking it is more economical, and better for the seedlings, to sow thinly in drills. To allow for cultural attention like weeding, hoeing, watering, &c., the seed- beds should not be more than 4 to 5 ft. wide, with an alley between, so that half the seed-bed may be attended to from one side and half from the other without having to tread upon the soil between the plants. The forest and other trees raised in large quantities from seed are Oaks, Beeches, Birches, Ashes, Poplars, Sweet Chestnuts, Horse Chestnuts, Elms, Hollies, Hawthorns, Hornbeams, Limes, Mountain Ashes, Planes, Syca- mores, False Acacias (Robinia), Maidenhair Trees (Gingko), Willows, Tulip Trees (Liriodendron), and such conifers as the Firs, Spruces, Pines, the Arbor Vitse, Cedars, Thuyas, Larches, Cypresses, &c. Apart from the forest trees, there are hundreds of others of a more ornamental character, chiefly used for the decoration of large parks and gardens, public places and squares, streets, &c. These are raised not only from seeds in the same way as forest trees, but in the case of special varieties, or when seeds are not ripened in abundance, they are also raised by means of cuttings, layers, buds, grafts, and suckers. The most impor- tant plants in this group and in the forest section are dealt with in Vol. II in the article on " Trees and Shrubs ", to which the reader is referred. Of late years a great trade has sprung up, chiefly amongst nurserymen, in ornamental flowering shrubs, which are grown in pots and gently forced into early bloom in Spring (January to March and April). The principal plants thus grown are Lilacs, Double Cherries, Azaleas, Almonds, Japanese Quinces, Wistaria, Double Plums, Cydonia Maulei, Pyrus spectabilis, Deutzia gracilis, Staphyllea colchica, Prunus triloba, Magnolia Soulan- geana, Forsythia suspensa, Ribes sanguineum, &c. &c. A trade also has sprung up again in clipped trees and shrubs of an ever- green character. Such trees as the Box and the Yew, the Poet's Laurel, and others are cut into various shapes, some more or less fantastic as shown in the photograph (fig. 1). They are usually grown in tubs, and are utilized for what some people call decoration, but others desecration, of large gardens. [j. w.] General Aspects of Commercial Gardening 13 Photo. Clias. L. Clarke Fig. 1. Clipped Trees and Shrubs Japanese Gardening 1 . Although the introduction of the beautiful Japanese plants that now contribute to the charm of British gardens belongs to the distant past, it was not until some fifty years ago that commercial cultivators gave serious attention to the Japanese flora with a view to obtain some other of its members for the further enrichment of our gardens. If until the middle of the last century Japan was not exactly a sealed book to the seeker after new forms of tree and plant life, the restrictions imposed upon the members of other nationalities were such as to render it extremely difficult for them to obtain access to the country, much less to explore meadow or woodland, or plain or mountain, and bring away on their return home the spoils of the ex- ploration. The removal of these restrictions by the opening of the Japanese ports to foreigners rather more than half a century ago gave 14 Commercial Gardening the desired opportunity for collecting some of the many beautiful trees, shrubs, and other plants that were likely to succeed under the climatic conditions that obtain in the United Kingdom, and placing them at the disposal of the general body of plant lovers. Then as now the nursery firms of this country were remarkable for their enterprise, and there- fore not slow to take advantage of the opportunity thus given them for enriching gardens with new and beautiful forms of plant life. As a proof of this one example will be sufficient. In April, 1860, the late John Gould Veitch, a member of the well-known Chelsea firm, left England on a voyage to the Far East, and arrived at Nagasaki in the July following. He remained in Japan about twelve months, and during that period he sent home a large number of trees, shrubs, and bulbous and other plants, and of these the greater proportion have proved of so high a degree of value as to obtain a place in gardens generally. Coni- ferous trees included Abies firma, A. microsperma, Cryptomeria japonica elegans, Juniperus chinensis aurea, Larix leptolepis, Picea Alcockiana, P ajanensis, P. polita, Pinus densiflora, P. parviflora, P. Thunbergi, and the varieties of Retinospora obtusa. The deciduous trees included the varieties of Acer palmatum, the climber Ampelopsis tricuspidata (or Vitis inconstans), and the plants Lilium auratum, Primula japonica and P. cortusioides. The introduction of so many kinds of first-rate im- portance within so short a period evinces much enterprise, for travel- ling in Japan was very different in those days from what it is at the present time. The Abies, Cryptomeria, Piceas, and Pinus represent species that rank high in their respective genera, and the varieties of Retinospora obtusa are so diversified in form and colour, and withal so attractive, that they have throughout the period that has elapsed since their intro- duction enjoyed a high degree of popularity and have been freely used in the creation of garden scenery. The varieties of Acer palmatum, in the varied form and colour of their elegant foliage, are recognized as forming a group of small-grow- ing trees of immense value for garden decoration; and Ampelopsis tri- cuspidata is used more largely in clothing wall surfaces than all the other climbers combined, and it contributes in no small degree to the amenities of town life. The richly coloured Primula japonica continues to be highly appreciated as one of the best of the moisture-loving plants for fringing streamlet and pool in shady positions, and as the result of the activities of various commercial horticulturists the varieties of Primula cortusioides have been so multiplied as to form a large group in which there is so great a range of colour as to greatly enhance their value for various decorative purposes both under glass and in the open. The plants thus briefly enumerated rapidly came into favour. They were largely used, and soon made an impression on the scenery of gardens where novelties of merit received a welcome. They greatly enhanced the interest and attractions of gardens in which they were given a place, and as a result they greatly stimulated an interest in Japanese plants, and General Aspects of Commercial Gardening 15 gave rise to so strong a demand as to tax severely the resources of nurseries for a long series of years, and have an immense influence for good upon a great industry. They had another effect in their relation to the garden, and that was to quicken an interest in rare and beautiful plants from other parts of the world, by showing that there were subjects other than timber trees and the common laurel suitable for furnishing the O garden. In the case of Lilium auratum there was a brisk demand for bulbs at a comparatively high rate, and when it became possible to supply them at a price which placed them within the reach of practically all owners of gardens, the demand increased to an enormous extent. For forty years or more the importations of the bulbs of this Lily have annually been on such a large scale as to represent a trade of consider- able importance and to occupy a prominent position in the business of those who are concerned with the distribution of bulbs. Lilium longi- florum, which was introduced to this country in the year previous to John Gould Veitch's voyage to Japan, has enjoyed a higher degree of popularity than even that of L. auratum, not because of its flowers being superior in beauty, but because of their adaptability for decora- tive purposes. To the florists they are of immense value, for they can be used more or less successfully in wellnigh all forms of the decorative art, and with the aid of the refrigerator in retarding the bulbs they can be had in abundance at all seasons of the year. British cultivators are no longer wholly dependent upon Japanese growers for their supplies of bulbs, but they annually obtain large im- portations from them. The demand for this beautiful and useful Lily is very great, and the importation and distribution of the immense numbers of bulbs that are annually required in market-growing establish- ments and private gardens has become so important a detail of com- mercial horticulture that one could wish statistics showing the exact quantities that annually reach this country from Japan were available. Lilium speciosum, which also forms an important part of the trade in Lily bulbs with Japan, was introduced from that country in 1833; but since that year the Japanese growers of Lilies have sent us varieties of this species which are so superior in the size, form, and colouring of their flowers as to surpass those of the typical white and coloured forms and to render them of quite secondary importance. Of much interest is Iris Kcempferi, which was introduced to this country from Japan in 1857, and attracted much attention when the large handsome and richly coloured flow T ers were first presented to public notice at the exhibitions, and began to make their appearance here and there in private gardens. For a time they failed to make the headway that was anticipated, and this was in a large measure due to the cultural details being then imperfectly understood. Many of those who planted this Iris in its varied forms failed to recognize the fact that to achieve success the roots must have the run of a rich and moist soil, an abun- 16 Commercial Gardening dance of moisture being especially necessary during the season of growth. Hence large numbers were planted in beds or the mixed border, without reference to their special requirements in the matter of food or moisture. The growth was consequently unsatisfactory, and in course of time their cultivation was greatly reduced. Within the past few years there has been a great revival in the interest evinced in this and other of the Japanese Irises. The lessons that the Japanese growers have been able to teach us have been taken to heart, and moist positions are selected for the moisture- loving Irises, and, if these cannot be provided, care is taken to main- tain the soil in a thoroughly moist state throughout the whole period when the plants are in an actively growing state. The influence of the Iris gardens of Japan has been felt in many gardens of this country, and in not a few, large plantings have been made on the lake side and along the margin of pools, and constitute delightful features. These examples are of interest as showing that if we cannot have displays of Irises equal to those which have made the gardens of Hori-kiri famous, we can with their aid have in this country floral pictures of wondrous beauty. Among the Japanese trees and shrubs that have been introduced but have not as yet been planted largely, mention may be made of Magnolia hypoleuca, which attains noble proportions, but does not produce its handsome flowers freely until it has attained a large size; the Japanese Horse-chestnut (^Esculus turbinata); the elegant Styrax japonicum; Betula Maximowiczi, a handsome Beech remarkable for its large leaves and yellow bark; Quercus acuta, Q. glabra latifolia, two Evergreen Oaks of merit. Then there is Daphniphyllum glaucescens, one of the most handsome of evergreen shrubs, and Vitis Thunbergi, which surpasses in brilliancy of colouring V. Coignetice, long so popular for clothing trellises, wall spaces, and tall pillars. With a fuller knowledge of the distinctive characteristics of the many beautiful trees, shrubs, &c., that had been introduced from Japan, and the increased facilities for becoming acquainted with the various phases of garden design that had long found favour in that country, it is not surprising that a strong desire should have been felt by many owners of gardens within the British Isles to create gardens more or less in accordance with Japanese ideas. Practical expression has in numerous instances been given to this desire, and, as might have been expected, with varying results. Where the principles governing the making of gardens on the lines followed by the Japanese landscape gardeners have been acted upon as closely as circumstances would permit, the result has been a distinct, interesting, and pleasing addition to the pleasure grounds. On the other hand, where but scant attention was given to principles, the results have not been altogether satisfactory. The Japanese garden, as we understand the term, is not a swamp, as suggested by some of the gardens that have come under our notice. Neither is it a lake surrounded by an irregular belt of trees and shrubs JAPANESE GARDENING TWO VIEWS OF JAPANESE GARDENS ERECTED AT LONDON EXHIBITIONS (Jas. Carter & Co.) General Aspects of Commercial Gardening 17 and a winding walk, with, it may be, a bridge or stepping stones to cross it at the narrowest part. The Japanese garden does not consist of one or two features, but of many, and one of the distinguishing characteristics of the Japanese landscape gardener is the skill with which he combines the features of, it may be, a whole countryside, in an area of quite moderate dimensions. Another attribute of his skill is the success that is achieved in maintaining the relative proportions of the several features, and also of the trees and shrubs with which the garden is embellished. In accomplishing this important object he has in many instances to use trees, ornaments, &c., of so small a size as to suggest to the Western mind that the garden is intended as a model on a reduced scale rather than for the enjoyment of the owner. The garden in Japan is regarded from a somewhat different stand- point from that which we consider it in this country. Here, to state the case generally, we provide a garden adapted to the requirements of the plants in which the owner is specially interested, with such embellish- ments as may be considered necessary; to the Japanese, plants primarily exist for the assistance they are able to render in the production of artistic effects, and are utilized accordingly. One of the principal rules governing the work of the landscape gardener in Japan is to follow nature as far as is practicable, and to arrange the arborescent and other forms of plant life in their natural associations. That is to say, plants which in a state of nature have their home on the mountain side are not to be brought down to those parts of the garden which represent 'the lowlands, and, it may be, used in the formation of a flowery fringe to running stream or silent pool. In like manner the plants that luxuriate in the moist conditions that obtain at the lakeside are not used in the clothing of the side of a hill or mimic mountain. The Japanese garden artist would appear to give ready adherence to this rule, for he can readily include in any given design the characteristic features of any given portion of the native landscape. Another rule of some importance is to avoid as far as practicable the planting of deciduous trees, with a few exceptions, in the more prominent positions of the garden. The exceptions are deciduous trees remarkable for the beauty of their flowers, such as the Cherries and Plums, which are not only immensely attractive when yielding their wealth of flowers, but are great favourites with the Japanese. If it is intended to plant a tree near the end of a bridge, one should be selected which will spread its branches over it, and cast a shadow on the water. It is not considered in accordance with the canons of garden-making to show the whole of the volume of water tumbling over rocks, and therefore it is enjoined that in selecting a tree for planting alongside a cascade that it will throw its branches partly over the rushing water. Shade-giving trees are considered the most suitable for planting near seats and tea houses, and Pines are the most generally selected for the purpose. Much the same rule applies to the planting of trees by the VOL. I. 2 is Commercial Gardening side of ponds and other small water areas, the object being to obtain a cool retreat during the summer's heat. The selection of positions for trees in the gardens is considered by the Japanese authorities as a matter of much importance, and they feel, as do those in this country who have had experience in such work, that when trees are planted without the exercise of sufficient judgment the desired effect is lost. For a long period Pines were the favourite garden trees, and they were trained to form round heads or to some quaint shape to give a distinctive appearance to the spot in which they were placed. Of late years Western ideas would appear to have had some influence upon the Japanese, for within the past decade or so trees more or less natural in growth have come into favour, and the trees with formal heads or contorted branches are no longer fashionable. The Japanese Maples, of which there are now so many beautiful forms in cultivation, are not always a complete success in British gardens, and this is due in many instances to a failure to plant them in positions most favourable to their full development. The Japanese, having a full know- ledge of the elegance that characterizes the habit of these trees when growing under natural conditions, and abundant opportunities for enjoying the glorious colour effects produced by their leaves when the breath of autumn has passed over them, freely use them in the creation of garden scenery. They by no means limit their selection to the kinds that do not take on their rich colouring until the summer months have run their course, but group with freedom the many fine forms of Acer palmatum that in the diversity in the form and colour of their leaves afford a rare opportunity for the garden artist to produce colour effects of the most beautiful description, extending from within a short time of the bursting of the buds to the fall of the leaf. These Maples are of much value in gardens, whatever may be their design, and particularly in those of small size; and although the demand for them continues to be great, there is room for an acceleration in the rate at which they are being planted. The free use of stone in the making of Japanese gardens is a point of much interest, and while it may not be regarded as of so much im- portance as the trees with which the garden is furnished, sufficient care and attention are bestowed upon its selection to ensure every piece being suited to the position in which it is to be placed. Especially noteworthy, also, are the stone ornaments, of which the lanterns of stone are the most important. These lanterns may be of granite, sandstone, or lime- stone, and they take us far back into the distant past. For many centuries they were exclusively associated with the temples that have a prominent place in many parts of the country; but in the course of the development of the landscape art some of the leading exponents conceived the idea of using them in the adornment of the garden, and within a comparatively short period their use became general. Stone lanterns are no longer confined to Japan, for larger numbers are annually imported, and many are the British gardens wherein several may General Aspects of Commercial Gardening 19 be found. These lanterns differ considerably in design, and there is no difficulty in selecting one that is well suited to the position it is to occupy, whether it be by the waterside, alongside the bridge of stone, or for forming a contrast to the brilliant colouring of the Azaleas or Irises, or the feathery growths of Bamboos and tall-growing grasses. It is one of the canons of the landscapist's art that these lanterns should be partly sheltered by trees, either at the back or front. In the water scenery that usually has a place in Japanese gardens stepping stones are freely used, and form walks that wind through the water garden and afford an opportunity for closely inspecting the Water Lilies, the Lotus, the Irises, and the many other beautiful plants that thrive in or near water. In some of the more extensive gardens bridges of stone are provided for crossing the deeper waters, but the quaint semi- circular bridges of wood which are now so well known are the most general. The tea house is an essential feature of the Japanese garden, and it may be mentioned that it is usually so constructed of Bamboos or light strips of wood as to allow the air to circulate freely through it, and it is assigned a position on the bank of a lake or pond, on a prominent island, or in some other part of the garden where scenes more or less beautiful can be readily seen. An essential feature of the Japanese garden is its bamboo framework clothed with the Wistaria, which in its season gives a wealth of the long pendent racemes of blue or white flowers; and even if the Wistarias fall short of the magnificent specimens at Kameido, a suburb of the city of Tokio, they afford displays of wondrous beauty. What has been accom- plished in Japan in the cultivation of Wistarias may be done in Japanese or indeed any other gardens in this country. Not less noteworthy for their value in beautifying the gardens of Japan are the double-flowered Cherries, such as Prunus pseudo-cerasus fl.pl., which are planted freely, and annually produce delightful displays. All the best forms that are grown in Japan are in trade collections in this country, and it is much to be desired that with the increased attention that is now given to Japanese gardens they may "be planted by the dozen, instead of singly, as is now usually the case. [o. O.] SECTION II The Science of Plant Growin i. SIMPLE AND COMPLEX CELL LIFE The successful cultivation of plants requires a close familiarity with their likes and dislikes, a knowledge of the conditions of their existence, and how to meet those conditions to the best advantage of the culti- vator; for the requirements of man are not always identical with the objects of the plants themselves. By dint of practice alone and close application to the art for a series of years one may become sufficiently expert to grow a limited number of kinds to great perfection, but the field for experiment and improvement is boundless in the domain of gardening. Not merely are there plants, flowers, fruits, and vegetables with which one is familiar, but new ones are constantly arising, differing in some respect from those that preceded them; and hundreds of others, whose cultivation is an undetermined quantity, or may have been known to the successful growers of bygone times and since forgotten, may be placed under the charge of the gardener. The traditions of the past have not merely to be maintained, but the gardeners of the present have to con- tinue the forward march of improvement, by introducing better methods of cultivation wherever opportunity occurs, by improving the fruits, flowers, and vegetables already under cultivation, and originating new ones by the various means and methods at command. The field of enquiry is wide enough for every class of worker, and the practical culti- vator may avail himself of the assistance at his disposal from various sources by acquiring a knowledge of the structure and nature of plants, just sufficient to enable him to comprehend the meaning of the information imparted by the more scientific worker. Simple Cell Life. A good conception of plant life in its simplest form may be obtained by an examination and study of some of the lower organisms, such as the green scum to be seen on damp walls or the trunks of trees, where the water runs down during rain. If a minute particle of this green matter (Protococcus viridis) is put in a drop of water and placed under a high power of the microscope, it will be seen to consist of numerous tiny green bodies of various sizes, invested by 20 The Science of Plant Growing 21 a colourless envelope or cell wall. Each individual constitutes a com- plete plant. The interior is filled with a particle of granular, jelly-like matter, stained green. This jelly-like substance has been named proto- plasm, and, as it is present in all living plants and animals, it is con- sidered the seat of life. It is the essential part of the plant, as we shall see presently. When any of the cells has reached full size, it divides into two equal parts, which become separate individuals, and repeat the history of their parent by feeding, growing, and again dividing. Those who would see- this process must needs burn the midnight oil, for one-celled green plants manufacture food from the atmosphere by day in preparation for dividing by night. Rain brings down many of these plants from the roof-gutters of the house, and if a drop of watei from the water butt is examined in summer or other suitable time it will be found to contain more or less numerous organisms, some con- sisting of a particle of green jelly, without the cell wall, and larger ones with an investing wall, but both sizes moving about rapidly. The movement is due to the rapid vibration of two slender thread-like portions of the protoplasm, without colour, and therefore invisible till something is put in the water to bring the organisms to a state of rest. After a time they lose these filaments, and become surrounded by a cell wall, like those on the damp wall. From the damp wall, or from the water in the butt, these lowly plants absorb their food, or rather the raw materials from which they manufacture it. Already we can see that the cell wall can be dispensed with as so much dead matter, while the naked protoplasm is still termed a cell, and is equally an individual plant. The Yeast Plant (Saccharomyces cerevisice), such as is used by the brewer, if put in any clear liquid containing suitable food (malt, for instance), the liquid, if stood in a warm place for some hours, will become cloudy or muddy, this being due to the rapid multiplication of the Yeast Plant. The temperature of the fermenting liquid is raised as a result of the chemical changes being brought about in the con- stitution of the liquid by the Yeast Plant. If a drop is examined under the microscope, the plant is seen to be oval, smaller than the Protococcus, but without the green colouring pigment of that, showing that it belongs to the great group of Fungi. It is also rapidly multiplying by budding at one end. The tiny protuberance or offset grows to nearly the size of its parent, and drops away as a new individual. The "clubbing" of turnips, cabbages, cauliflower, and other members of the Crucifer family is due to another fungus, which lives within the roots during summer and other mild periods, causing great swellings to arise. At this period each individual multiplies rapidly, and rests enclosed in a cell wall of its own during winter; but with a rise of temperature in spring the protoplasm quits the cells and unites in a jelly-like mass, which moves through or over damp soil in quest of fresh plants to attack. From these three plants it will be seen that the protoplasm possesses 22 Commercial Gardening certain properties. They can absorb food materials, manufacture the food, breathe, give off certain ingredients as waste products, reproduce them- selves, and in two cases are possessed of motion, the capability of which resides in the protoplasm itself (fig. 2). The Protococcus can manufacture its own food from raw materials, by reason of the presence of green colouring matter under the influence of light. The Yeast Plant must be supplied with malt, grapes (in wine-making), or some other food already in an organ- ized form. As the club-root fungus (Plasmodiophora brassicai) is also colourless, it must have organized food, and, as it feeds upon living plants, it is a parasite. All of them absorb oxygen to give them energy, and as it combines with some of their substance, carbon dioxide is given off. The process is equivalent to breathing or respiration, as in animals, and is abso- lutely essential to all living things. 2. STRUCTURE OF THE HIGHER PLANTS Fig. 2. Protoplasm The Growth of a Cell. The three plants already SZSSiSSlio* considered consist of a single cell, varying chiefly in of Arrows size during their lifetime. Other plants, in an as- cending scale of organization, consist of more or less numerous cells united in a variety of ways to form the plant body, either in the form of filaments, or flat plates of cells, as in freshwater or marine algae. The larger seaweeds form a tissue resembling stem and leaves, but a true stem and leaves are first met with in Mosses and Sphagnum. The Ferns are still more . highly organized, by having true roots, stems, and leaves. The flowering plants are the most highly organized, and gardeners are chiefly concerned with them. The tiny Duckweeds, which cover still ponds in summer, are flowering plants of very exceptional structure, for they consist merely of a small mass of green cells, with one or more root hairs from the under side. The smallest of all (Wolffia arrhiza) has not even a root hair. The tallest tree and the smallest plant, amongst flowering subjects, consist alike of an aggregation of cells, built up in some definite form, according to the kind. A full knowledge of plants may be obtained by a study of proto- plasm and its protective covering the cell wall together with their behaviour when acted upon by light, heat, air, and moisture. A very young cell may be taken from the leaf of an apple tree, when beginning to unfold. It may be oval or nearly round. Under a high power of the microscope the wall appears double, but each individual has its own wall, and the other is the wall of the cells that abut on the one under The Science of Plant Growing examination. The interior at first is entirely filled with protoplasm, in the centre of which is a denser, oval body the nucleus consisting of a granular groundwork of protoplasm, denser at its margin, and having a fibrillar network of granules embedded in it. The nucleus plays a very important part in the division of full-grown cells. As the cell increases in size, cavities make their appearance in the protoplasm, filled with cell sap and air, and this continues till the cavities unite and the protoplasm can only form a lining to the wall, with a few bridles connecting it with the layer of proto- plasm surrounding the nucleus in the centre (fig. 3). Streaming movements of the proto- plasm may often be observed in the living cells of various plants (the direction being indi- cated by arrows in fig. 2). The large granules to be seen embedded in the protoplasm are chlorophyll or leaf green. The further history of this cell depends on whether the tissue requires more cells or not for its full development. If it does, then the nucleus elongates into spindle form, the protoplasm forms a mass at each end of the spindle, the two masses being joined by threads. A layer of protoplasm (the cell plate) then extends across the cell from wall to wall, and from this layer a new partition is formed simultaneously and continuously. Thus two cells are formed. The common partition later on splits into two, so that each daughter cell has Fig. 3. Isolated Cells (1 and 2) with and (3) without Nuclei highly magnified 123 Fig. 4. Changes in the Protoplasm of the Cell Nucleus during its Division 1, The Nuclear Fibrils distributed through the whole Nucleus. 2, The broken-up Nuclear Fibrils arranged as the Nuclear Plate. 3, The elements of the plate separating from one another. 4, The same elements forming two skeins at the poles of the Spindle. (After Guignard.) Very highly magnified. its own complete wall and a half of the original nucleus (fig. 4). If the full-grown cell does not intend to divide, the remainder of the protoplasm is used up in thickening the walls, or is drafted away into younger and growing cells. The empty cell is now dead for all time coming, though it may exist for a thousand years or more, if it forms part of the stem of a giant Sequoia gigantea of California. The cell wall at first consists of cellulose, a substance closely allied to starch and sugar, all three being made up of the chemical elements carbon, hydrogen, and oxygen, in different combinations, and all becoming black when burned. 2 4 Commercial Gardening Fig. 5. Section across Wood Cells, showing concen- tric layers of woody matter surrounding a central cavity Scolopendrium Fig. 6. Elder Pith, consisting of aggrega- tions of Cells magni- fied Changes in Cell Walls. Although the cells of the higher plants may be all very much alike when they begin life, they vary immensely in size, shape, and structure by the time they reach full development, their ultimate construction being dependent upon the functions they have to perform for the wellbeing of the plant. The most common change is the thickening of the cell wall internally, by successive layers of cellulose, till the internal cavity is nearly filled up, and the cellulose gets converted into wood (fig. 5). The cells of the pith remain thin -walled (fig. 6). Those on the outside of the trunk of the Cork tree, Elm, Ash, &c., get thickened like those of the wood; but in this case the material is con- verted into cork, which is very light and almost impermeable by water. A thin layer on the outer face of all leathery leaves, like those of the India Rubber and Palms, forms the cuticle, and is also of the nature of cork. Various Forms of Cells. With the exception of lowly plants like the duckweeds, the flowering plants gene- rally furnish examples of cells of great variety of form and length. Those which become thread-like, but thickened inter- nally, are termed wood cells (fig. 7), but wood fibres when they become pointed at the ends, with the thin portions spliced or overlapping, so as to form continuous masses of wood (fig. 7). The thickening is by no means always uniform, for small spots are left unthickened in pinewood, and such are known as pitted wood cells (fig. 7). The thickening may take the form of single or double spiral bands in the stems of Melons and Cucumbers (fig. 8), ring-like bands, or a mixture of an- nular and spiral ones (fig. 8). In ferns the bands unite in the form of a ladder. These elongated cells may be placed end to end and the partitions broken down, thus forming continuous vessels, like a hose pipe, for the rapid convey- ance of liquids. Sieve tubes are formed in the inner bark of stems by the dividing plates of vessels becoming perforated by small openings. Plants with a milky juice, like the Lettuce, Dandelion, and India Rubber } have cells which join in a variety of ways and break down the inter- Tracheids Fibres Fig. 7.-Wood Cells The Science of Plant Growing vening partitions, becoming continuous and forming what is known as laticiferous tissue (fig. 8). Spiral and Celandine Laticiferous Annular Vessels Tissue Dandelion Laticiferous Tissue Plant Tissues. All the above forms of cells and many more unite in certain definite relations to one another, forming a tissue (fig. 9). Most flowering plants, Ferns, Lycopods, and Selaginellas have representatives of various forms of cells, wood fibres, and vessels in their tissues, and are spoken of as fibro-vascular plants, and consti- tute the most highly developed members of the vegetable kingdom. A mushroom is not a fibro-vascular plant, as it is made up entirely of branching threads of thin-walled cells. Uses of Different Cells. The thickened outer cells of leaves and young stems are of a protective nature, so far as the cuticle is concerned, while the interior is thickened to impart strength. Wood fibres give rigidity to the stems of herbaceous plants and in a greater degree to trees, which have the greatest number of them; and they, in conjunction with the continuous tubes or vessels, serve for the rapid convey- ance of liquids, containing ingredients of plant food, as well as elaborated food being carried to the points of growth or to be stored. The laticiferous Fig. 9. Cut illustrating various tissues. To the left Spiral Vessels, followed by long Conduct- ing Cells. These are succeeded by Cellular Tissue or Parenchyma. In some of the square cells are Crystals of Oxalate of Lime. In the longer cells are groups of Needle-like Crystals called Raphides. To the extreme right are Pitted Cells. 26 Commercial Gardening tissue is more obscure, but some of the contents are of the nature of stored food. Some cells are set apart entirely for the purpose of marrying and reproducing the plant. The other cells have their respective duties, and have neither time nor opportunity for this. [j. F.] 3. PLANTS OF DISTINCTIVE CHARACTER Plants with Chlorophyll. Most plants with which the gardener has to deal contain chlorophyll or leaf green in their leaves and the super- ficial tissues of their stems, at least during the first year. It consists of a green pigment colouring the large granules that develop it and lie embedded in the protoplasm, but are capable of shifting their position if the light is too strong for them. These green granules, under the influence of sunlight and electric light, are the agents by which all raw food materials are chemically changed in character and converted into organized material suitable for building up the plant body and enabling it to store food for future use, or to provide for its offspring. The light must be accompanied by the other necessaries of plant life, such as heat, air, and moisture. Green plants are thus able to manufacture their own food and lead an independent existence. Crotons, Dracaenas, Coleus, and other plants with highly coloured leaves have chlorophyll in their tissues, but this is obscured by the presence of other colouring matters, diffused through the cell sap. Plants without Chlorophyll. Amongst flowering plants many species, including the Broomrape (Orobanche) that lives attached to the roots of Clover, and the Dodders (Cuscuta) that live on Clover, Nettles, Hop, and other wild plants, have no chlorophyll in their tissues, and cannot manu- facture their own food. They must needs attach themselves to the roots or stems of certain green plants and absorb their food in an organized form, thus robbing and injuring their hosts to a greater or less extent. The Broomrape sometimes attaches itself to the roots of Pelargoniums in pots, and one of them, kept under observation by the writer, was allowed to flower, The result was that the Pelargonium was stunted in growth and failed to recover itself, even after the parasite was removed. Such plants are termed parasites, because they absorb their food from living plants. The great group of fungi have no chlorophyll in their tissues, and many of them are parasites, like the Club-root fungus of Cabbages, the Mildew and Rust of Roses and Chrysanthemums, the Rust and Brand of Wheat, and many other cultivated plants. A large number of them are very minute, one-celled, and capable of producing diseases in plants, man, and other animals. In these two latter cases they owe their existence indirectly to green plants as the first and only manufacturers of organic food. On the other hand, many fungi are harmless, because they live upon dead and decaying plants and animals, and are termed saprophytes. The Mushroom is one of them, and lives upon fermenting manures and other decaying matter. So far it is the only plant without chlorophyll, that is The Science of Plant Growing 27 of any importance to cultivators in this country. All fertile soils swarm with minute, one-celled fungi or microbes, living upon dead matter and converting much of it into a soluble form, suitable as food for green plants. In a word, they are the agents alike of decay and fertility, preparing the soil, the manure, and leaf heaps for the use of the higher plants. Lichens are composite plants, consisting of a fungus and a small green alga, working in co-partnership for their mutual benefit. Even some of the higher plants, including several forest trees, have messmates or co- operators amongst fungi, large enough to be seen by the naked eye (fig. 10). The fungi closely invest the fibrous ends of the roots and absorb the food they require from the trees. On the other hand, some of the waste products of the fungi are required by the trees to V^M* 1 complete their bill of fare. It is not yet determined to what extent this co-operation prevails among cultivated plants, but some plants diffi- cult to cultivate may really require this kind of assist- ance. It is well known that Rhododendrons and other plants belonging to the same family like a peaty soil and hate lime in any form. In all probability the lime de- stroys the microbes in the peat that are essential to the welfare of the Rhododen- drons. Desert Plants. Echeverias, Crassulas, and Aloes, from South Africa and Mexico, have fleshy stems and leaves. Cacti, including Epiphyllums from Brazil, Mamillarias and Phyllocacti, from Mexico and other warm and dry parts of America, are also fleshy but have dispensed with leaves to economize their liquids. In their native habitats they get very little rain, and make a point of storing up what they do get, while their struc- ture is such as to prevent the liquids from escaping too freely. Under cultivation many of them enjoy liberal treatment in summer, when the temperature is high and they are making their growth, but they must be kept relatively dry in winter when at rest and the light is bad. With few exceptions they like a relatively high temperature even in winter. They cannot give off moisture like thin-leaved, green plants, consequently water must be withheld almost entirely during winter, otherwise they would decay wholesale. A gardener can readily diagnose a plant of this character, without knowing its name or from what country it comes, and give it the proper treatment accordingly. Fig. 10. Illustration of Co-partnership or Symbiosis 1, Roots of the White Poplar with Myeelial covering. 2, Tip of a Root of the Beech with closely adherent Myeelial covering ; x 100 (after Frank). In these cases the Myeelial threads on the roots are of fungous origin, deriving nourishment from the roots on which they grow, but at the same time supplying food material to the roots. 28 Commercial Gardening Other plants of dry countries produce hard and wiry leaves, like the Grass tree of Australia (Xanthorrhoea), and must likewise be kept on the dry side during winter. The Rushes (Juncus) of our marshes and river banks belong to the same family, but their stems are very largely made up of loose, spongy tissue, surrounded by a thin layer of more solid structure, almost like a skin. They are therefore capable of giving off large quantities of water at any time when circumstances require it. Some plants of dry climates and arid soils and situations clothe themselves with a more or less dense coating of hairs; and in proportion to the density of this covering must they be kept dry in winter, otherwise they would sooner or later get into an unhealthy condition and ultimately perish. The roots are usually the first to suffer from an excess of moisture, but the functions of the leaves and other parts also get deranged. The common Stock, in a wild state, inhabits dry chalk cliffs, and all parts of the stems, leaves and calyx are densely covered with star -shaped, branching hairs. Seedlings under cultivation are extremely liable to damp off while quite young, if kept too close and moist in the seed pans or boxes. The exces- sive moisture renders them liable to attack by the " damping-off" fungus (Pythium debaryanum). It is not usually regarded as a desert plant, but it serves to explain a similar difficulty when brought under cultivation from its dry, wild habitats. Clammy-leaved Plants. At first sight these may not seem peculiar, when Petunias and Salpiglossis are mentioned, for there are many other examples under cultivation. They are plants, however, which delight in sunshine and flower best in dry weather. The writer has seen Pelar- goniums and other plants remain stunted and lose their foliage in a dry garden on the chalk formation, in a droughty summer, while Petunias, Gaillardias, and other clammy-leaved plants were the only flowering sub- jects in the beds. While young and making growth they enjoy fairly liberal watering, with a moist atmosphere, but to bloom freely they must have plenty of light and air, and be kept dry overhead. The viscid hairs with which they are covered enable them to recuperate themselves during the night from the deposit of dew in the open ground. Insectivorous Plants. Many plants, whose root system is not well developed, or which live in swampy places, where they have difficulty in procuring a sufficiency of nitrogen in the usual way, have evolved some peculiar contrivances for eking out the supply. The Sundews (Drosera), Venus Fly-trap (Dionasa), Pitcher Plants (Nepenthes), (fig. 41). Butterworts (Pinguicula), and Bladderworts (Utricularia), belong to this class, and many of them are cultivated. By various means they manage to capture and detain insects and other small creatures, which they digest or dissolve, absorbing the nitrogen. The Sundew (fig. 11) develops on the upper surface of its leaves numerous tentacles, each terminated by a sticky gland. Flies alighting upon a leaf get held fast by the viscid matter, while the other tentacles close upon their victim. The protoplasm now forms a " ferment", and the liquid is spread over the PERPETUAL CARNATIONS i. Carola. 2. White Perfection. 3. Victory. 4. Enchantress . (Half natural size) The Science of Plant Growing 29 fly till dissolved, when the juices are reabsorbed. A stone or other object would cause the infolding of the tentacles, but if such objects contain no nitrogen the tentacles soon unfold, without having produced any chemical changes in the protoplasm, thus proving that nitrogen was the element of food required. Climbing" Plants. The Convolvulus, Wistaria, and Scarlet Runner are 123 4 Fig. 11. To show contraction induced by the contact of insects. Tentacles on Leaf of Sun-dew (Drogera) 1, Glands at the extremity of a Tentacle; x 30. 2, Leaf with all its Tentacles inflexed towards the middle. 3, Leaf with half the Tentacles inflected over a captured insect. 4, Leaf with all the Tentacles extended. 2, 3, and 4x4. examples of plants that climb by twining their stems round some support- ing object. If the top or free end of a Scarlet Runner is observed at different times during the day, after it has commenced to run, it will be seen to be swinging round in a wide circle, and should it chance to touch a stake, string, wire, or other support, it commences immediately to coil tightly round the same and to make rapid progress. The stem is sensitive to contact and this sensitiveness resides in the protoplasm, being one of its properties. Scarlet Runners grown in the field without stakes often twine round one another, but without proper support they never attain the length of which they are capable, nor do they produce so heavy a crop. The saving of labour and the extra cost of stakes are the chief reasons for this method of culture. Sweet Peas, garden Peas, Cucumbers, Melons, Vines, and others climb by special structures known as tendrils. The leaf stalks of Clematis and Tropseolum twist round supporting objects in a similar fashion, and they as well as tendrils are sensitive to contact. [J. F.] 4. THE ROOT AND ITS WORK The Primary Root. The first structure that emerges from the interior of a germinating seed is the primary root or radicle, which goes perpen- dicularly down into the earth. If the minute structure of the tip of this is examined it will be seen to consist of very small square cells at and behind the growing point (fig. 12). Around and in front of this is a layer of brick -shaped, corky cells, most of which are empty and dead. This is Commercial Gardening the root cap, which is intended to protect the tender growing point as it pushes its way amongst the particles of soil. The nature of a young root may readily be seen by filling a punnet with light sandy soil and scatter- ing some Mustard seed thinly over the top. Stand it in a warm, moist, shady place for a few days till the seed germinates, and then in a well-lighted position. From the sides of the radicle numerous hairs arise, enter the soil in a horizontal direction, and place themselves in close contact with the par- ticles of soil (figs. 13, 14, 15). These are the root hairs, and their function is to absorb water containing food in solu- tion. The interstices or spaces between the particles of soil are filled with air, or should be, for land plants, but the par- ticles themselves are covered with a thin film of water, and this is all that the root hairs can absorb. If the interspaces are filled with water, the soil is water-logged and the radicle and root hairs cannot breathe, but soon get asphyxiated and perish. The radicle does not absorb water at the tip but some way behind it, and only while the outer walls remain quite thin. The root hairs continue their work for a few days or weeks, then die away and leave no trace behind; but as the radicle lengthens and sec- ondary roots are formed, new ,^ % root hairs are continually Fig. 12. Section through the Root Tip of Pentstemon. The bowl-shaped mass at the tip is the root cap; x 60. Fig. 13. 1, Seedling with the long absorp- tive cells of its root (" Boot Hairs ") with sand attached. 2, The same seedling: the sand removed by washing Fig. 14. Koot Tip of Pentstemon with Root Hairs penetrating between the particles of soil ; xlO fig. 15. Root Hairs or Absorptive Cells of Pentstemon with adherent par- ticles of earth being produced, thus tapping fresh areas for food. In Dicotyledons generally the primary root is permanent, and, if undisturbed, may attain a great size and age in forest trees. From an early stage of growth it commences to give off secondary roots which branch repeatedly, permeating the soil in every direction with their finer ramifications or root fibres. In The Science of Plant Growing 31 Monocotyledons, like Lilies, Daffodils, Onions, Palms, and Grasses, the primary root soon ceases to lengthen or dies, but its place is taken by numerous, secondary, and even adventitious, fibrous roots. Some of these attain a considerable thickness in large Palms and Screw Pines (Pan- danus), but in grasses they remain slender and fibrous (fig. 16). Importance of Primary and Fibrous Roots. In general terms roots serve to fix the plant in the soil. The primary, descending root of forest trees is of considerable importance to many of them, like the Oak, Elm, and Ash, in preventing them from being overturned during gales and hurricanes of wind. To gardeners it is of leading importance in the case of such root crops as Carrots, Par- snips, and Beet. Great care is taken in preparing the soil to a considerable depth, and the seeds are sown where the plants are to grow till they reach maturity. No trans- planting is permissible. If the primary root or radicle were broken, a shapely taproot would be impossible. All of them could be transplanted with the greatest facility, and, with care, almost every root would grow, but they Grafs -Fibrous d Root would be short, stumpy, forked, misshapen, unsaleable, and useless except for cattle. A deeply worked and well -pulverized soil is necessary to enable the radicle to descend perpendicularly without twist- ing or bending between stones and hard lumps; and if well manured for some previous crop, the radicle and slender, lateral fibres will be well able to forage for the requirements of a large and shapely root. It is quite different in the case of Cabbages, Apple, Pear, and other fruit trees, because transplanting multiplies the number of fibrous, feeding or absorb- ing roots. The more fibres upon the roots of Cabbages, Onions, and the like, the sooner they get established in their permanent positions when transplanted. Taproots are undesirable in fruit trees, because they often get down into uncongenial subsoils, while plenty of fibrous roots near the surface induces early fruitfulness and permits of feeding. Relation of Soil to Roots. As already observed above, the root hairs of plants apply themselves very closely to the particles of soil, in order to absorb the thin film of water adhering to them. This film contains plant food in a state of solution, and in greater quantity than in the root hairs themselves, but at the same time the solution is very dilute and the root hairs have to absorb a much greater quantity of water than is actually required by the plant in order to get a sufficiency of food. The nature of a soil bears a definite relation to its fertility. A sandy soil, being made up of relatively large particles, can hold only a very limited quantity of water, because the spaces between the particles are large and filled with air. If manure is applied it rapidly decays and much of the plant food in it is washed away into the drainage by rain. If liquid manure is applied, most of it runs away. On the other hand, the particles of a clay soil are much finer, hold more water and plant food, either in solid or 32 Commercial Gardening liquid form. If some of the latter is poured on a clay soil, it can abstract ammonia, free potash, phosphoric acid, and various salts containing plant food and hold them till they are absorbed by plants. All clay soils, if not originally fertile, can readily be made so by artificial means, and it only remains for the cultivator to make them sufficiently porous by good tilth to enable the roots of cultivated plants to penetrate freely and collect the food stored. Water and Air Roots. While the roots of land plants can only absorb the film of water adhering to the particles of soil, the roots of water plants are able to absorb the free water with which they are surrounded. They are greatly elongated, much more branched than those of a land plant, and thin -walled, without cuticle or root hairs on their surface. A land plant may produce water roots, as when Hyacinths are grown in glasses of water. Another good instance in nature may often be seen where the roots of trees penetrate tile drains and actually choke them up. If the roots of a land plant are immersed in a vessel of water they continue to absorb water for a time, but soon develop true water roots and the earlier or original fibres die. They get their food and air dissolved in the water surrounding them. One peculiar form of air root may be seen in Orchids. The root is surrounded by a membrane of cells, several layers deep, more or less thickened, per- forated with holes, and filled with air. They ab- 17. -Dahlia-Tuberous Root sorb rain containing plant food in solution, and deposited at first in the form of dust on or near the root. If such roots develop on the outside of a flower pot or basket they must not afterwards be buried either in soil or Sphagnum. The writer has seen a fine batch of Moth Orchids (Phaleenopsis) killed by placing the small baskets inside larger ones and filling the space between with Sphagnum. In many Aroids that produce aerial roots the surface is loose and spongy and more or less densely covered with root hairs which absorb moisture from the air. Tuberous Roots. The primary and secondary roots of the Dahlia become greatly swollen and spindle-shaped (fig. 17). The thickened portion is intended for the storage of reserve material with which to make a good start the following season in the production of the flower stem. The material stored is inulin. The base of the stem and the upper part of the root of the Turnip becomes greatly thickened and tuber-like, storing starch for the requirements of the flower stem in the second season. In the case of the fleshy, thickened taproots already mentioned, the Carrot and Parsnip store starch for the same purpose as the Turnip, and, all being good for food, they are cultivated for this special purpose by man. The same applies to Beet, which stores a sugar very like cane sugar. The Science of Plant Growing 33 Work of the Roots. In summarizing the above remarks it may be said that roots fix the plant in the soil, commence to absorb watery solu- tions of plant food at a very early stage; they breathe, and, in the case of land plants, must be grown in well-drained soils, while they are modified in certain plants to perform similar functions in water, or air, and have become fleshy and constitute a storehouse of reserve food in the cases men- tioned. Some substances of plant food are soluble in pure water; others are rendered soluble by the presence of carbon dioxide, lime, and other ingredients in the soil. The root hairs and the younger slender fibres of the root are able to dissolve other substances. Their cell walls are actually permeated with acid sap, and this dissolves substances with which they come in close contact. If a small slab of polished marble is placed in the bottom of a flower pot in which a Sunflower, Broad Bean, or Scarlet Runner is grown during the season, and examined in autumn, it will be found that the roots have left their exact impression by eating away the polished surface. If the ingredients of plant food absorbed were to remain unchanged inside the root hairs the sap would soon be of the same density as the watery solution outside the membranous wall, and the inward cur- rent would cease; but their chemical nature is continually being changed in one or other part of the plant, and the cells abutting on those having the root hairs absorb the food from the latter, and so on in succession, until it is carried into the vascular tissue of the root, and thence into the stem. This absorption goes on continually night and day, so long as the con- ditions are favourable. The result is that a current of sap is being pushed into the interior of the plant by the activity of the roots, and is known as "root pressure", some of the effects of which will be discussed in the chapters on the stem and the leaf. Energy is required by the roots in order to perform all this work, and that is obtained by the absorption of oxygen from the air in the process of breathing. For this reason alone, trees and shrubs should not be planted too deeply, nor should soil be heaped over the surface, where such are already established. We have frequent evidence of large trees being killed outright in a few weeks by the deposition of 3 to 5 ft. of muddy soil or clay over their roots, which cannot breathe nor perform any other function for want of air. Badly drained soils have similarly evil effects. When the soil in flower pots is over-watered, or the drainage hole gets stopped up by worms, the roots cannot get sufficient air, and their functions become deranged, or they die. The Food absorbed by Roots. Of the ten elements of plant food that are absolutely essential, all of them, except carbon and a small quan- tity of nitrogen, are absorbed by the roots. They are oxygen (the free oxygen of the air is used only in breathing), hydrogen, nitrogen, sulphur, phosphorus, potash, calcium, magnesium, and iron. They are not absorbed in this simple form, but in various combinations termed salts (such as nitrates), acids, &c. Oxygen and hydrogen are absorbed in the form of water; nitrogen in the form of ammonia and nitrates; sulphur as sulphates; phosphorus as phosphates; potash and lime in combination with sulphur, VOL. I. 3 34 Commercial Gardening phosphorus, nitrates, &c.; and iron in a variety of compounds. Most of the above are present in sufficient quantity in soils generally, and when land requires manuring, nitrogen, phosphorus, and potash are usually most deficient. Lime is occasionally deficient, and is useful for a variety of purposes. Except in the case of Leguminous crops, such as Peas, Broad Beans, Dwarf Beans, and Scarlet Runners, nitrogen is always necessary unless the soil is very fertile. Leguminous plants have bacteria in small nodules upon their roots, and these bacteria are capable of fixing the free nitrogen of the air. Farmyard manures are very valuable in light soils by increasing their power of holding water, independently of the plant food they contain. Contractile Roots. Apart from the functions already described, a large number of bulbous plants are provided with roots which have the Fig. 18. Seedling Plant of Gourd (Cucurbito Pepo) with Radicle, Caulicle, and opposite Cotyledons. Liberation of the Cotyledons from the cavity of the Seed or Fruit Husk, showing in the central figures the little peg or radicle that serves to fix the seedling. power of contracting at certain periods, and thus pull down the bulbs or corms deeper into the soil. These roots are known as " contractile ". They are generally thicker and fleshier than the more fibrous feeding roots, and are recognized by the transverse wrinkles or rings upon them. The young or new corms of Gladiolus and Crocus, and the young bulbs of many Liliums and other bulbous plants, are all provided with such roots. In the case of seedlings, Dr. Scott says, in his Structural Botany, that the young bulb "is gradually drawn down year by year owing to the shortening of the adventitious roots. As the end of the root attaches itself firmly to the soil, the effect of the contraction is to exert a downward pull on the bulb. The upper part of the root is alone capable of contraction, and is much thicker than the rest. The inner cortex is the actively contractile tissue; as it contracts, the external layers are thrown into transverse wrinkles. The Science of Plant Growing 35 New roots of this kind are formed each year, until the bulb has reached its normal depth." [j. F.] 5. THE STEM AND ITS FUNCTIONS The Seedling" Stem. Almost any seedling will serve to show the origin and development of the stem from an early stage of its growth. Fig. 19. 1, 2, Seedling of Nasturtium (Tropceolwn majus). 3, 4, Seedling of Water Chestnut (Trapa jiatam) with section of seed. 6, 6, Seedling of Austrian Oak (Quercus austriaca). 7, 8, 9, 10, Stages in the germination and growth of Date Palm (Phoenix dactylifera) with sections. 11, 12, 13, Seed and germination of same of Reed Mace (Typha Shuttlewwthi). 14, 15, Seedling of Sedge (Carex mtlgaris). 1-8 nat. size ; 9, 10, x 8 ; 11-13, x 4 ; 14, 15, x 6. It forms part of the embryo, while still in the seed. A Stock, China Aster, Cabbage, or Gourd seedling (fig. 18) will serve the purpose. Between the ground and the seed leaves the short, upright portion is the first visible part of the stern, to which various names have been given, including 36 Commercial Gardening cauiicle, which means little stem. Structurally it is mado up of cells, fibres, and vessels, built up in the form of tissue characteristic of a stem. Its functions are to hold up the seed leaves to the light and supply them with water and food materials. Between the seed leaves the first bud of the plant, known as the plumule, will be noticed. It is really the apex of the young stem, covered with the rudiments of the first true or rough leaves. Many variations are met with amongst seedlings. For instance, in the Scarlet Runner, Broad Bean, and Oak the seed leaves remain in the seed, below-ground, during and after germination. In these cases the cauiicle remains very short, the seed leaves do not make their appearance, and the plumule is the first part to rise above ground. The cauiicle under- goes modification in other ways in certain plants. The upper portion of the tuberous swelling of the Turnip and Radish consists of the cauiicle, enlarged and fleshy, to serve as a store for reserve food. The Growth and Thickening- of the Stem. As the plumule grows and develops into a stem of some length in the Stock or China Aster, it is seen to be self-supporting, because the thickness and woody matter in the interior is proportionate to the height. The leaves of the Cabbage are much larger, and the stem becomes greatly thickened to support them. The stem of the Gourd becomes enormously lengthened in proportion to its thickness, but has to lie on the ground unless supported. If the stem of any of these plants is cut across it will be found to have a core of pith, consisting of thin-walled cells, surrounded by a layer of wood of greater or less thickness, and that again by a bark of no great thickness, and covered on the outside with a skin or epidermis. Such sterns of the first year are usually green, because they contain chlorophyll, and are capable of manufacturing plant food. The skin of green stems also has air pores, or stomata, such as leaves have, and takes in oxygen from the atmosphere for the purpose of breathing. The above, in general terms, is the structure of a stem of one season's growth. In order fully to understand the thickening of a stem it will be neces- sary to consider the structure of a shrub or tree, say the stem of an Apple tree of some size. If the stem is cut across, the pith (fig. 20) will be found in the centre, and probably of small size, owing to the pressure of wood upon it. This is surrounded by a number of layers of wood, each ring corresponding to one year's growth, and thus the age of the tree may be determined. This wood is made up of cells, wood fibres, and vessels more or less thickened internally. Surrounding the wood in winter is a thin layer of thin-walled cells, termed the cambium (No. 8), to be considered presently. Outside of the cambium is a ring or rind forming the bark, now of considerable thickness by comparison with that of a Stock or Gourd. It has lost its skin or epidermis (No. 1), and in place of the stomata, openings loosely filled with cork cells, and known as lenticels, may often be observed on stems or branches not too old. These are breathing pores. A large portion of the bark is made up of corky tissue (No. 2), gradually breaking away from year to year, while the inner The Science of Plant Growing 37 portion is younger and more fibrous. Collectively the various members of the rind are known as bark. Some of the fibres are thickened, and known as hard bast (No. 5), while the inner cells remain thin-walled, constituting the soft bast (No. 6). Archangel mats are made from the hard bast of the younger portion of the bark of the Lime tree. Sieve tubes (No. 7) are included in the hard bast, which serves to give toughness and pliability to stems and branches. The bark, collectively, also serves to protect the cambium from injury and the wood from decay; hence one good reason for careful pruning and judicious lopping of all trees whatever. 3*5678 9 10 11 12 Fig. 20. Portion cut from a Branch of a Leafy Tree x about 200 (diagrammatic) 13 1, Superficial coat (Epidermis). 2, Cork (Periderm). 3, Cortical parenchyma. 4, Vascular bundle sheath. 5, Hard bast. 6, Soft bast. 7, Sieve tubes. 8, Cambium. 9, Pitted vessel. 10, Wood parenchyma. 11, Scalariform vessels. 12, Medullary sheath. 13, Medulla or pith. The Cambium. Even in winter, when the trees are leafless and com- paratively at rest, the thin-walled cells of the cambium are small and filled with protoplasm; it really constitutes the only live portion of the tree at this period. It forms a thin, cylindrical jacket to the trunk of the tree, and gradually tapering cylinders to each branch and twig, till continuous with the small core in each live bud on the tree. The cambium descends to the roots in like manner. When the temperature rises in spring the cells are excited into rapid growth, and, with abundant supplies of stored food close to hand, they soon reach full size, divide, grow, and multiply rapidly. The cells on the inner side develop new fibre-vascular bundles, side by side, in a continuous ring all round last year's wood. Those on the outside of the cambium form new hard and soft bast. Thus the wood increases in Commercial Gardening thickness by the deposit of a new ring on the outside of its mass, while the bark thickens by the deposit of a new ring on the inside of last year's one. The existence of the cambium explains the art of budding a Rose, grafting a scion or shoot of one Apple tree on to another, inarching a young Vine on the rod of an old one, and the grafting of shoots of a Clematis, Tree Pseony, and Wistaria on to the roots of another for the purpose of increasing their numbers. The object in each case is to get the only live portion of the scion of the tree, shrub, or climber into contact with the cambium of the stem and root, respectively, used as stocks. The cambium of the one coalesces or joins with that of the other, and forms a new layer of wood over the old. If the grafted portion of an Apple or other tree were examined after one hundred years, the old cut surfaces would still be present, for mature or ripened wood, being dead, never unites. The whole of the wood of a tree, after it is fully ripened, is dead, though it may exist for one thousand years or more, protected by the bark, and be of service to the tree. Fig. 21. Section of Dicotyle- donous Stem, showing central pith, three zones of wood, and bark on the outside (diagram- matic) Fig. 22. Section of Stem of Palm and Fern Dicotyledonous and Monoeotyledonous Stems. The above descrip- tions relating to the thickening of stems and the cambium layer apply entirely to Dicotyledons. The structure of a three-year-old stem is repre- sented by fig. 21. Trees and shrubs are less numerous amongst Mono- cotyledons, whilst herbaceous types in cultivation are very numerous. Structurally they are all much alike, whether herbs, shrubs, or trees, of one or many years' duration. Palms, some species of Pandanus, and a few Bamboos are the only plants of tree-like habit or dimensions in the class. The stem of a Palm may be taken to consider details of structure (fig. 22). There is no pith in the centre, nor bark on the outside. There is a skin on the epidermis, and that is permanent. The body of the tree is made up of short-celled ground tissue, and distributed through this are very numerous strands or bundles of fibro-vascular tissue. They are isolated in the ground tissue, and when the cells, fibres, and vessels of which they are composed have reached their full size, and thickened their walls, they can make no further growth, as there is no cambium. Towards the circum- ference of the stem the fibro-vascular bundles are the most numerous, and The Science of Plant Growing 39 Fig. 23. Lily Scaly Bulb. Onion Tun icated Bulb as the cells of the ground tissue in that region thicken their walls greatly, it follows that the outside of the stem of a Palm is very hard. A seedling- remains without a stem till the leaves have attained a large size and a certain number, when the stem rises up almost of the same thickness throughout. As Palms generally do not branch or increase the number of their leaves, the thickening of the stem is unnecessary. Some species of Dracaena thicken their stems slightly by some of the cells of the outside of the ground tissue retaining the power of dividing and form- ing new tissue like the rest. The stem of a Fern consists of ground tissue, with an inter- l W were sown in the open air. SHOWING ELECTRIC SEED-CLEANING MACHINERY (James Carter & Co.) SHOWING MACHINERY FOR FILLING SACKS WITH SEED SEED WAREHOUSES Methods of Propagation 73 Name of Plant. Date of Sowing. Date of Germinating. Number of Days. African Marigold ... ... April 4 April 9 5 African Marigold* ... ... ... ... 8 29 21 Antirrhinum, Sunlight The Bride Aquilegia coerulea ... ... ... ... March 3 M 7 3 March 13 13 24 10 6 21 ,, glandulosa , , hybrids 3 3 28 23 25 20 Auricula, Alpine 3 ,, 18 15 Calampelis scabra April 8 April 19 11 Calendula, Meteor ... ... ... ... 4 10 6 Callistephus hortensis * Candytuft 8 ,, 11 22 , 15 14 4 Centranthus macrosiphon* Chrysanthemum, tricolor ... Chrysanthemum, tricolor* 8 4 8 8 22 14 22 22 14 10 14 14 Dahlia, double 10 15 5 French Marigold ... ... ... ... 4 11 7 Gaillardia arista ta ... ,, 5 12 7 ,, grandiflora ,, 5 8 12 12 7 4 Gilia tricolor* ,, 8 ,, 22 14 Godetia ... ... ... ... ... 4 8 4 Godetia* ... ... ... ... ... ,, 8 ,, 22 14 Hibiscus africanug 8 22 14 Hollyhock, double ... 4 11 7 ,, single ... ... ... ... Ma. h 3 March 1 1 8 Ipomoea purpurea ... ... ... ... April 4 April 14 10 Lavatera arborea, var. Nicotiana affinis ... ... ... ... ,, 10 March 3 15 March 13 5 10 ,, sylvestris ... ,, 3 24 21 Papaver nudicaule ... ... ... ... April 4 April 12 8 ,, ,, double Pea, Everlasting 11 8 15 ,, 19 4 11 Petunia grandiflora ... ... ... ... March 3 March 12 9 Pyrethrum aureum ... ... 1 >, 7 6 Solanum giganteum ... 6 25 19 ,, pryracanthum ,, robustum ... 3 3 25 ,, 25 22 22 ,, Warscewiczii Stocks, Ten Week 3 April 4 25 April 10 22 6 Sweet Sultan ... 10 5 Whitlavia grandiflora Zinnia elegans 4 5 9 9 5 4 ,, Haageana 4 ,i 10 6 The table on next page shows the number of days it took various vege- table crops to germinate from seeds sown in the open air. Vitality of Seeds. While some seeds retain their vitality or power of germinating for twenty years or more, it is generally safer to utilize fresh and well-ripened seed to secure good plants. The stories circulated as to the seeds of "mummy" wheat germinating after two thousand or three thousand years have been discredited long ago, and need not be considered. As a rule, fleshy seeds like Peas, Beans, Acorns, Horse- chestnuts, Sweet Chestnuts, and Walnuts lose their germinating powers more readily than smaller and less fleshy seeds; but the latter also deteriorate if kept more than two or three years. In the case of Cucumbers and Melons, growers generally consider that they obtain a 74 Commercial Gardening Name of Crop. Date of Sowing. Date of Germinating. Number of Days. Beet, "Blood Red March 21 April 21 31 Dell's Black ,, 27 23 27 Broad Bean, Early Long Pod Carrot, Early Scarlet Nantes April 1 4 29 21 28 17 ,, Long Surrey Bed ... March 14 17 34 French Bean, Canadian Wonder July 14 July 25 11 Lettuce, All the Year Round March 19 April 4 16 ,, Commodore Nutt Feb. 2 March 12 39 ,, Paris White March 19 April 4 16 Onion, White Spanish April 1 29 28 Parsnip, The Student March 21 30 40 ,, 27 22 26 Pea, Veitch's Perfection July 14 July 23 9 Spinach, Victoria April 1 April 1 7 16 Turnip, Early Snowball March 14 April 1 18 > > ., 27 13 17 greater percentage of plants from two-year-old seed than from one-year- old, which would rather indicate that they require a further period to mature properly after being taken from the fruit and cleansed. Seed Sowing". Seeds are sown in the open air either "broadcast" or in " drills ", and under glass in pots, pans, or boxes of varying sizes. In the latter case the gardener mixes his compost beforehand, and drains his seed pans or pots more or less carefully and elaborately according to the class of seeds he intends to sow. Special pains are taken with minute seeds such as those of Begonias, Gloxinias, Rhododendrons, &c., and with the spores of Ferns. The gritty surface soil is rendered very fine by pass- ing through sieves of small mesh, and when pressed down firmly makes a fairly solid rooting medium for the plantlets, and also prevents the seeds from dropping down too far from the light. In the case of Orchids, which are now raised from seeds in thousands, the dust-like seeds are sown on the surface of the mossy or fibrous compost in which the parent plant is growing, the little plants being transferred to thimble-like pots when large enough for the purpose. In the open air, market gardeners and farmers prepare their soil also in accordance with the nature of the seeds. For small seeds the ground, after being ploughed or dug, is well harrowed or raked, and rolled if necessary to secure sufficient firmness. When large quantities of seed are being sown it is more economical and quicker to use a drilling machine. The seeds are put in a box, and drop through a slot at regular intervals in the drills that are made as the machine is drawn or pulled over the surface. The depth of the drills and the distance apart are regulated beforehand. Generally speaking, however, seeds are sown far too thickly, and in the case of such crops as Carrots, Parsnips, Turnips, Beet, Mangels, Peas, and Beans about 95 per cent of the seedlings have to be destroyed to make room for the others to grow. The waste is not so great with crops that are to be transplanted, as every plant almost may be utilized. When large areas are to be sown broadcast a sowing fiddle (fig. 61) Methods of Propagation 75 is sometimes used. This contrivance takes its name from the fiddling action of the operator when distributing the seeds. It consists of a light canvas-covered box frame, which is suspended by a strap from the right shoulder, and is carried under the left arm. At the base of the box is a neck with a controlling slide through which the seed passes, its flow being made continuous by a jigger action from an eccentric from a spindle which carries at its bottom a distributing disk. This disk, which has four radiating ribs, is actuated by means of a thong which forms the string of the bow, and which is passed once round the spindle. When recipro- cated, as in fiddling, the bow causes the disk to revolve rapidly in alternate directions, thus giving the seeds a throw of 15 to 30 ft. Where Radishes are grown extensively under glass the sowing fiddle is often used for sowing the seeds. Generally speaking, however, it :'v-: is more of a farmer's than a s. gardener's implement. v| Cutting's. A very large &* number of plants may be raised '. : ;:: by means of cuttings of the stems '!; : ; : .'; or shoots. Soft-wooded or her- ;/.'; baceous cuttings having leaves "X are used in many cases, the shoots '///. being in a half-ripened condition, - : - : that is, neither too young and sappy on the one hand nor too old, dry, and woody on the other. Fig. ei. sowing Fiddle Such cuttings, according to the hardy or tender nature of the plant, are usually inserted in sandy or gritty soil, and most of the leaves are stripped off to check evaporation of moisture from the tissues through the stomata or breathing pores. One, two, three or more leaves are retained, according to the nature of the plant, so that a certain amount of assimilation may be carried on and induce a " callus " to develop over the base of the cutting. Once the callus is formed from the coagulated sap, roots are soon emitted, and the cutting then becomes an established and independent plant. As a rule, stem cuttings are cut immediately beneath a joint, because at that point the fibrovascular bundles containing starchy food matters are closer together, and the callus forms more quickly from the descending sap. While the cuttings of some plants (e.g. shrubby Calceolarias, Pent- stemons, Snapdragons, Phloxes, &c.) root freely in cold frames, others require warmer and more genial surroundings, and must be placed in a hotbed or propagating frame with bottom heat. Indeed, even with hardy plants, the application of bottom heat will often induce cuttings to "strike" or root more readily than they would in cooler surroundings. Commercial Gardening Fig. 62. Begonia Gloire de Lorraine : Stem Cutting In some cases (e.g. Heaths, Epacris) great care is exercised to encourage roots to develop. The pots or pans in which the cuttings are to be inserted are carefully drained with clean crocks to within an inch or so of the rim, and a compost consisting of 1 part peat and 3 parts silver sand is used for the cut- tings. Glasses are placed over them for some weeks, to keep a moist atmosphere around them, and each day superfluous moisture is wiped from the glasses to prevent injurious dripping on the cut- tings. The cuttings of such plants as Zonal Pelargoniums, Fuchsias, Calceo- larias, Dahlias, Begonias (fig. 62), Phloxes, Pentstemons, Snapdragons, Carnations, Pinks, Lobelias, Aucubas, Roses, Heliotropes, Euonymus, Golden Privet, Skimmias, and many others root readily in any ordinary garden compost of a somewhat gritty nature if kept shaded from brilliant sunshine, and occasionally sprinkled overhead when there is a tendency for the air to become too dry. Woody Cutting's. Many hardy trees and shrubs may be raised from leafless cuttings of the well-ripened young shoots. The best time to take these cuttings is about the end of October and during November, although many will also root freely if taken in spring just when the sap is beginning to rise. With hard- wooded cuttings the basal half, being the ripest or most mature, makes the best cut- ting, and if taken with a "heel" of the older wood attached it is almost certain to root. The cuttings vary from 1 in. or more to 1 ft. in length, and the larger ones may be inserted about three -fourths of their length in the soil when placed out- of-doors. In this way such plants as Gooseberries, Currants, Roses and Rose stocks like the Brier and the Manetti, Dogwoods, Brooms, Cotoneasters, Diervillas (Weigela), Forsythia, Jasmines, Kerria Mock Orange (Philadelphus), Flowering Currant (Ribes san- Fig. 63. Shoot of Skimmia japonica Rooting Methods of Propagation 77 Fig. 64. Leaf Cutting of Begonia Gloire de Lorraine A shows old leaf from base of which new plant is arising. guineum), Willows, Shrubby Spiraeas, Tamarisk, Skimmias (fig. 63), and many others, are readily raised. While small herbaceous and leafy cuttings are inserted with a dibber, which is used for mak- ing a hole and packing the soil round the base, long woody cuttings are inserted in trenches made with the spade, or they may be inserted with a dibber. In the first case a line is stretched the length of the row, and a trench with a vertical side is made with the soade. The cuttings are then placed against the ver- tical side of the trench and pushed into the soil, the distance between the cuttings being about 3 or 4 in. The soil is placed against them and trodden down firmly with the feet, being afterwards levelled. When several rows of hard-wooded cuttings are to be inserted, about 1 ft. is left between the rows, to allow room for weeding and hoeing during the season of growth. Vines may be raised from cuttings inserted in the open air in the way indicated. As a rule, however, they are raised from single eyes in- serted in small pots in heat. Clematises may also be raised from cuttings in the same way. With some evergreens, like Aucubas, quite large pieces of a plant having several leafy branches will root readily if placed in coconut fibre or leaf mould with a little bottom heat. Leaf Cutting's. Many plants may be raised simply from leaves. The well-known Begonia Gloire de Lorraine and its relatives are largely raised in this way as well as from stem cuttings. Single leaves with stalk are inserted in sandy soil, several in a pot or pan. When placed in heat they soon root and develop Fig. 65. Leaf Cutting of Achi- menes showing development of Catkin-like Ithizomes and young Leaf Commercial Gardening young plants from the top of the leaf stalk, as shown in the sketch (fig. 64). Achimenes are also raised extensively in this way (fig. 65), as are also Gloxinias, foliage and other Begonias, Echeverias, Kleinias, Cras- sulas, Pachyphytons, &c. In the case of Gloxinias and foliage Begonias the leaves are laid flat on the soil, and have slits made across the midrib and main veins with a sharp knife. They are kept in position by small stones or pieces of broken pot, and kept moist and warm, and soon develop little plants from the slits. In the case of the Indiarubber plant (Ficus elastica), while the single leaves will develop roots, as shown in the sketch (fig. 66), and remain fresh for many months, they seem to be incapable of develop- ing plants. Fig. 66. Leaf of India- rubber Plant (Ficiis elastica) Rooting Fig. 67. Offsets from a Stonecrop (Seduin dasyphyUum) 1, Entire plant, nat. size. 2, 3, 4, Offsets at different levels on the stem in the axils of the leaves. 5, Offsets from floral region. The thick scaly leaves from the bulbs of many Liliums, if inserted in sandy soil, will produce little bulbs at the base, and these in the course of two, three, or four years will attain the flowering stage. Echeverias are readily propagated in the same way, the detached matured leaves giving rise to plants in due course. Many other fleshy plants may be increased from their leaves, as shown in the annexed cut of Sedum dasyphyllv/rn (fig. 67). Some Orchids (e.g. Thunia Marshalliana) may be raised from stem cuttings, as shown in the annexed drawing (fig. 68). The stems of Ficus elastica, cut up into pieces each containing one leaf and an eye, root readily in a temperature of 75 to 80 F. Dracaena stems cut up in the same way but without leaves, also root freely, and produce plants when buried Methods of Propagation 79 about 1 in. deep in a hotbed of coconut fibre. The tops of Crotons, Dracaenas, Araucarias, Aralia Sieboldi, and others also root when inserted in a similar hotbed. Ringing". This method of propagation may be called overhead layer- ing. It consists in making an upward or circular slit in the stem of a plant that has become too tall or leggy. Some sphagnum moss and leaf mould is then tied round the wound, and is kept damp with the syringe every day. In a short time the elaborated descending sap from the leaves develops a callus and a mass of roots through the moss. When a sufficient number of roots has been produced, the rooted head is severed and potted up. In this way tall Dracaenas, Crotons, Cordylines, Aralias, Ficus elas Fig. 68. Stem Cutting of Thunia Marshalliana A, Old stem showing fibres from joints. B, Young shoot with roots at base (i nat. size). Fig. 69. Aerial Layering tica, American Carnations, &c., may be propagated, as well as by other methods mentioned. If considered worth while, trees with branches too far from the ground might be propagated in this way, but the trouble would be to maintain moisture round the ringed portion. The sketch (fig. 69) shows how this method of propagation may be adopted for trees and shrubs, using a pot with a slit in one side for the purpose. Root Cutting's. By cutting up the roots of certain plants into pieces 2 or 3 in. long, and covering them with about 1 in. of gritty soil, it is possible to raise new plants. This method of propagation may be prac- tised about October and November, of in. February and March, the root 8o Commercial Gardening cuttings being inserted in a hotbed of moderate temperature. Some plants like Horse-radish and Sea-kale are easily and generally raised in this way; while such weeds as the Bearbind, Dock, Thistle, Dandelion are also in- creased quite as readily by chopping up the roots. Other plants that may be raised by means of root cuttings are Anemone japonica, Acanthus mollis, Boeconia, Dictamnus Fraxinella, the Sea Hollies (Eryngium), the Globe Thistle (Echinops), the Oriental Poppy (Papaver orientale), Statice latifolia, &c. Many kinds of trees and shrubs like Hawthorns, Plums, Apples, Pears, Quinces, Roses, Poplar, Mulberries, False Acacias (Robinia), Sumach (Rhus), Paulownia, Sophora, &c., may be propagated from root cuttings. Layering 1 . This method of propagation consists in making an incision in a branch or shoot, and then bending it down and covering with soil. Border Carnations are usually propagated by layering. In the open air the work is done about the end of July and during August. Non-flowering shoots are slit upwards with a sharp knife in a fairly well -ripened portion, thus forming a "tongue". The layered shoots are pegged into the soil with hairpins or pieces of bent wire, and are covered with a nice gritty soil, and given a good watering. At the end of three or four weeks a mass of fibrous roots are emitted from the callused surface of the tongue. Each rooted layer may then be severed from the parent plant which has been feeding it, and may be planted out at once, or potted up to be kept in cold frames during the winter. In the case of American or Perpetual-flowering Carnations the shoots may be layered whenever they are sufficiently ripe; but it is found more convenient, as a rule, to raise them by cuttings, or by " ringing ". Many trees and shrubs are propagated by layers when they cannot be raised in any other way, or when they are raised most quickly by that method. The young shoots near the ground are bent down and covered with soil, being kept in position by means of bent wires or wooden crooks. Some plants root readily from the joints without any incisions being made, but others are slit in the same way as Carnations, care being taken to keep the tongue open or away from the shoot. In fig. 70 a shoot a is shown pegged down at 6, while a stake c is placed to the aerial portion to keep it erect. In fig. 71 the tongue of the shoot is shown at 6, while another method is shown on the right at /, where a ring of bark is taken off the wood. It will be noticed that all Fig. 70. Layering a Woody Shoot Methods of Propagation 81 Fig. 71. Layering by Tongueing and Ringing buds are rubbed off on the portion of stem beneath the soil, while they are retained on the overground portions shown at 1, 2, and h. Many fruit - tree stocks, like the Crab and Paradise for Apples, Mussel and Brussel Plums, Pears and Quinces, the Mahaleb Cherry, ai-e usually raised from layers, as are also many ornamental shrubs like Magnolias, Cratsegus, Osmanthus, Phillyrea, Viburnum, Hamamelis, &c. In the case of such plants as Vines, Clematis, Wistaria, Lapa- gerias, and others with long flex- uous shoots, the latter are bent down at intervals of a foot or two, as shown in the sketch (fig. 72), the portions e being pegged down and covered with soil 6, the overground portions d being furnished with buds. Owing to the snake -like ar- rangement of the shoots this system of layering is known as " serpentine ". Many plants like Goose- berries, Black Currants, Loganberries, and Blackberries, &c., layer them- selves naturally when the stems are allowed to lie upon the ground, and they may be propagated in this way if necessary. Many other woody plants could also be propagated by layering if necessary or desirable. Runners. A runner is a slender whip-like shoot sent out from the parent plant to root at some distance away, and at certain intervals to produce fresh plants. The Strawberry is the best-known example of a runner-bearing plant, and gar- deners readily seize upon this character to raise thousands every year. New varieties of Strawberries, of course, are only obtained from seeds after a more or less lengthy process of cross-fertilizing and selec- tion ; but, once established, new varieties are also propagated from runners. Other plants besides the Strawberry throw out " runners " or "stolons", examples of which are met with in the Sweet Violet, the Houseleek, some Saxifrages (like 8. sarmentosa), and these may be used for propagating purposes. In the case of Couch Grass the underground stolons are produced with more than desirable frequency and pertinacity from the cultivator's point of view. Suckers. A sucker is an aerial shoot springing from an underground stem or root. Suckers usually have some fibrous roots attached to them, VOL. I. 6 Fig. 72. Serpentine Layering 82 Commercial Gardening and when severed from the parent may be regarded almost as estab- lished plants. Such plants as Chrysanthemums, Plurns, Black Currants, Raspberries, Blackberries, Loganberries, produce suckers freely, and may be propagated by them. In the case of Apples, Plums, Peaches, Necta- rines, Roses, &c., any suckers arising are, of course, from the wild stocks, and are detached as early as possible, unless they are required later on to form stocks themselves. Offsets. Most true bulbous plants, like Tulips, Daffodils and Narcissi, Hyacinths, Liliums, Snowdrops, &c., produce offsets from the parent bulbs. When the offsets are detached and replanted they produce flowering plants the following season, or a season or two afterwards. If some bulbous plants e.g. Daffodils and Snowdrops are left undisturbed for years they increase rapidly and produce numerous bulbs. Nerines, Vallotas, Hippeastrums, Crinums, Pancratiums, &c., also develop numerous offsets from the base of the older bulbs. Corms as produced by Gladioli, Montbretias, Crocuses, Colchicums, are known as "solid" bulbs as they have no coats as in Tulips and Daffodils or thick scaly leaves as in Liliums. They produce numerous offsets, but the old corm always shrivels up or vanishes while the new ones are forming on top. In such corms as those of the florists' Gladioli (Brenchley- ensis. Childsi, Lemoinei, and Nanceianus) numerous seed-like outgrowths are also to be seen. These are known as " spawn " and will produce new plants in a year or two if sown like seeds in nice gritty soil. In the case of tuberous plants like the Arum Lily, Jerusalem Arti- choke, the Potato, the Dahlia, &c., large numbers of tubers or tuberous roots are produced, each one of which will give rise to one or more plants. The tubers of the Artichoke and Potato, for example, if cut into pieces each containing an " eye " or bud, will produce several plants. The tuberous roots of the Dahlia and the herbaceous Pseony, however, must have a piece of the old stem attached, as no shoots are produced by the roots themselves. The tubers of Begonias, Cyclamen, and Gloxinias may be cut into pieces each with an eye or sprout. Underground sterns or rhizomes, as met with in the German, Florentine, and other Irises, Solomon's Seal, Mint, &c., are utilized for increasing the stock, each portion having a bud being capable of forming a new plant. Bulbils. Many bulbous plants like Lilium bulbiferum and others produce seedlike bodies known as "bulbils" in the axils of the aerial leaves. These bulbils are capable of producing plants if sown in suitable soil and grown on for a year or two. (See fig. 24, p. 39.) In some Ferns, e.g. Asplenium bulbiferum, A. biforme, Woodwardia radicans, little plants also called " bulbils " appear on the fronds, and from these large numbers of plants may be raised quickly without having recourse to sowing spores. These bulbils may be regarded in the light of aerial offsets. (See fig. 46, p. 59.) Division of the RootstOCk. A very large number of herbaceous perennials, both hardy and tender, are more readily increased by splitting Methods of Propagation up or dividing the tufts into several portions, each containing a supply of roots. This operation is done either in the spring or in the autumn. If plants flower naturally during the spring and summer months they are usually best divided in the autumn; but if they flower in late summer and autumn they are generally best divided in the spring. Cir- cumstances, however, may necessitate plants being divided at any season if it is desired to raise stock quickly without risking the life of the plants. Many plants that do not produce seeds or spores can only be propa- gated by division. Many Orchids, Ferns (e.g. Adi- \ o antum Farleyense, and Nephrolepis), and Bamboos are raised in this way, as it is the only one possible. Budding-. The art of budding consists in remov- ing a bud from one plant and inserting it partly be- neath the bark in another growing plant in such a way that it will obtain nourishment from its host, and eventually bear flowers or fruits. In the open air budding is generally prac- tised from the end of July and during August, but may be done as late as September under abnormal circumstances, such as a particularly hot and dry F 'g- 73. Shoot of Apple arising from Bud inserted in Stock close T.I to Ground Line, the Stock being cut back to form a stake to which season, when the sap may y0 ung shoots are tied not flow freely until the weather becomes cooler, or until rain falls. Under glass, budding may be practised almost at any season when the buds and stocks are in a suffi- ciently advanced condition, but from January to March is the usual time. Only dicotyledonous plants can be budded or grafted, because they possess a cambium (see p. 36), and it is essential also that the bud or graft and the stock should be in the same family and closely related. Otherwise the difference in constitution and nature might be so great that union would be impossible. Thus Roses are budded on Brier or Manetti Rose stocks; Apples on Crab-apple, Paradise, Doucin, or free stocks; Pears OD Pear or Quince stocks; Plums, Peaches, Nectarines, Apricots, Cherries on Plum stocks, and so on with other groups of plants (fig. 73). 8 4 Commercial Gardening The bud or graft is really a kind of parasite. The plant that springs from it has no roots of its own. It is dependent upon the roots of the stock for the crude sap, which is pumped up into its stems and leaves from the soil. This crude sap, however, is elaborated in the leaves of the scion, and not in those of the stock; hence the changes are such that the leaves, flowers, and fruits exhibit the features and usually possess the nature of the scion and not of the stock, Laburnum adami being a notable exception. There are several ways in which buds may be inserted, but the best and commonest method is that known as shield budding or T budding (fig. 74). The dormant buds are taken from a ripened shoot of the current year's growth, each bud having a small piece of leaf stalk attached to serve as a handle. The stocks in which the buds are to be inserted in July and A August should have been planted the previous October or November to get them well estab- lished by then. Buds are either inserted as low down the stem and as near the root as possible, or they may be inserted on the topmost shoots of a stock 3 to 10 ft. high. In either case a transverse slit is made with a sharp budding knife, and an upper cut about 1 in. long is made to meet it, the two cuts forming the letter T. The flat bone handle of the knife is gently pushed in the upper slit to open the bark, and render it easy to insert the bud, which has been severed in advance and placed between the lips while the slits were being made. In taking a bud the chief point is to select one that is dormant, and neither too young near the top of the shoot, nor too old or sprouting from near the base. If a flat piece of wood is taken off with the shield of bark it should be removed, care, however, being taken not to tear out the body of the bud with it. Some Continental and American budders do not trouble to detach the piece of wood, but in British gardens it is customary to do so. The bud being inserted, the bark is then tied round it with raffia or worsted thread, carefully but firmly, to exclude the air. In two or three weeks the bud will have united with the stock, and it will be necessary to cut the tying material. An expert budder will bud from 500 to 700 stocks per day, or more, with the assistance of an intelligent lad to clean the stocks and tie the buds after insertion. Grafting". Unlike budding, where a single bud is used, grafting con- sists in affixing a shoot of one plant with two or more buds on to the stem of another in such a way that the cambium layer of one must come face to face with that of the other. The shoot is called the "scion", and the plant on which it is placed is called the " stock " the latter being already well rooted and established for twelve or eighteen months in advance to ensure complete success. As in budding, so with grafting the stock and scion must be closely related, and belong at least to the same natural Fig. 74. Showing Stock A, with T-cut at a for reception of Bud B, side view of which is given at e, and inner face view at d Methods of Propagation family. There are several ways in which grafting may be done, and the principal ones will be mentioned. Whip Grafting-. This is the best method when the stock and scion (or graft) are nearly of the same thickness, and thousands of fruit trees are propagated in this way every March and April in the open air. Preparatory to grafting taking place the stock is usually "headed" back in January or February; that is, the stem is cut off, leav- ing a stump a few inches high sticking out of the ground. The cut surface Fig. 75. A Graft or Scion A, cut and tongued at T to fit top of Stock B; at o is shown the Graft and Stock united, tied, and waxed or clayed The soon heals, as little or no sap is rising at that cold period of the year, grafts or scions, which always consist of ripened one-year-old shoots, are also severed about the end of January or February, and are "heeled in" in bundles under a north wall. This prevents them starting into growth prematurely, and keeps the sap in them in a less active condition than if the shoots were allowed to remain on the parent plant. The grafting period in the open air being reached, that is, in March and April, a slanting cut is made in the stock as shown in fig. 75, and a nick is made in it to form a tongue. The graft or scion, having two or three buds attached, is also cut obliquely, as shown in the figure, and a tongue is also made in it so that it shall fit into the one made in the stock. The two cut surfaces should be about the same length and width if possible, but it is not essential. One edge of the scion, however, must be made to fit flush with the edge of the stock, to bring the cambium layer of each face to face, because it is by means of the new cells Fig. 76. Showing how Badly Treated Young Fruit Trees are grafted in some Market Gardens 86 Commercial Gardening Fig. 77. Cleft Grafting from the cambium that union is to take place. The graft being properly fitted to the stock it is then tied round securely with raffia, or matting, or worsted thread, after which the joint is covered over completely with grafting wax, or clay made into "pug" by mixing it with a little chopped hay or straw. A good grafting wax may be made by boiling in a saucepan some beeswax, resin, and Russian tallow in equal proportions. While still warm (not hot) this mixture, which should be of the consistence of treacle, is easily applied with a little brush or flat piece of wood. A rough-and-ready method of grafting as practised in some market gardens is shown in fig. 76, taken from an actual specimen. Cleft and Rind Grafting". In the case of old t.ees, having the stems many times thicker than the scions, whip grafting could not be conveniently done. The stocks are headed back at the proper season, and at the proper time a slit is made in the bark with a strong- bladed knife, or a cleft is made with a chisel, as shown in fig. 77 at a. The latter is not a good way to graft, as it leaves a fissure open in the stem, in which water collects and rots the wood later on. The slit with the knife is best, and the bark may be gently opened outwards with the point of a small chisel or flat piece of steel to allow the graft, which has been cut obliquely to form a wedge, to be pushed in easily. Two or three similar grafts may be inserted in one stem if necessary, and if the bark only is open, without splitting the wood, the process is known as " rind " or " crown " grafting, as shown in fig. 78. Saddle Grafting-. When the stock and scion are about equal in diameter this method may be adopted, but it is not so good as whip grafting and is also more troublesome to perform. As shown in fig. 79, the stock A is cut up on both The graft or scion B, having several buds, is split up the centre, and each half is thinned to make it fit astride the tapering stock, and so that the inner bark of stock and scion are flush with each other at least on one side. Cleft Grafting Triangular Notch Grafting Fig. 78. Forms of Grafting Fig. 79. Saddle Grafting sides to form a wedge ending at c. Methods of Propagation Fig. 80. Side Grafting Side Grafting*. This is a form of whip grafting, but the stem is not cut away completely above the point of union. A notch or slit is made in the side of the stock, as shown in fig. 80 at a, b, and the scions are inserted and tied. It will be noticed that horizontal or vertical shoots may be grafted in this way, and after the new shoot has grown to a good length the stocks may be cut off just above the point of union. Herbaceous Grafting 1 . This is ap- plicable to plants having non- woody stems, and is practised only for the sake of curi- osity. Potatoes have been grafted on Tomatoes, and vice versa ; Cauliflowers on Cabbages; Zonal Pelargoniums, Dahlias, &c. It seems, however, to be of real value in the Australian Glory Pea (Clianthus Dam- pieri), which grows freely when grafted on the stems of seedling Colutea arborescens, but will often perish on its own roots. Coniferous trees have been grafted with young shoots in the forest of Fontainebleau and other places, the 'modus operandi, as described by Du Breuil, being as follows : " When the terminal shoot of the stock a (fig. 81) has attained about two-thirds of its length, it is cut back with a horizontal cut to the point where it begins to lose its herbaceous con- sistence and commences to become woody. The young leaves are cut off between a and d, a distance of between 2 and 3 in., leaving, however, about two pairs at the top d d, to attract the sap. Thus pre- pared, the stock is split down the middle to the depth of 1 in. or 1^ in. The scion 6 is cut wedge-shaped, and introduced into the split, so that the commence- ment of the cuts on each side of the scion may be nearly 1 in. below the top of the stock. The scion should be cut at the place where its consistence is similar to the part of the stock where it is to be in- serted. Its diameter ought to be as nearly as possible equal to that of the stock. The graft being placed, it is secured with coarse worsted, commencing the tying at the top and winding it down to the lower part. In the case of delicate species it is well to wrap paper round the grafted part as a protection against the drying action of the sun and air. The shoots at c are then broken at about | in. from their bases. Five or six weeks after grafting, the cuts will be completely healed; the tie may then be removed, and the two portions d furnished with leaves at the top of the stock should be cut off", otherwise they might give rise to buds, which, in pushing, would weaken the graft." Fig. 81. Herbaceous Graft- ingConiferous Trees 88 Commercial Gardening Root Grafting". Many plants are propagated by inserting a short shoot in a root of a relative or by side grafting. Most of the Tree Pseonies are raised by inserting a shoot in a cleft of a tuberous root of Pceonia officinalis, making the edges fit flush on one side, and then tying them up with raffia, &c. Shoots of Wistaria are also inserted in the fleshy roots of the same plant, as shown in fig. 82, while garden varieties of Clematis are grafted in thousands on the roots of the common C. Vitalba. Inarching* or Grafting 1 by Approach. This method of propagation was, no doubt, suggested originally by the fact that boughs of trees that rub against each other and wear away the bark become united later on by means of their cambium layers. Inarching is thus a kind of grafting, but differs in that each of the plants to be united is growing on its own roots. It is often practised on Vines. A shoot of a desirable variety is cut and tongued on one side to fit into a similar cut and tongue on the undesirable one that may be worth retaining on account of its state of development, and to avoid replanting and remaking of the borders. When the inarched shoot has become firmly united it is severed from its own feeding base, while the stock to which it is attached has the portion above the inarched scion also cut away, thus leaving the lower portion of the stem and the roots. In this way a new variety takes the place of the old one without much trouble. Bottle grafting" is a form of inarching, and has been practised in connection with Oranges, Vines, Oleanders, and other woody-stemmed plants. A ripened shoot is taken, say of a Vine, about 1 ft. long. It is cut about 4 or 5 in. long, and tongued on one side about the middle, to tit into a corresponding cut and tongue on the stock. It is tied on securely, but the base of the shoot is stuck into a bottle of water. The latter should be replenished from time to time, fresh rainwater being preferred, and a few lumps of charcoal may be put in to keep it fresh for a longer period. [j. W.] Fig. 82. Boot Grafting Wistaria A, Shoot inserted in root B and tied. SECTION IV The Science of the Soil i. INTRODUCTORY When a man intends to grow fruits, flowers, or vegetables for profit his first consideration is the "soil". This constitutes his chief raw material, and he knows that if he makes a mistake in its selection it may lead him to ruin, or become such a drain upon his resources and labour that his life becomes one of drudgery, anxiety, and worry. In these days there is a danger of a good cultivator ignoring the teachings of his own practical experience, and trusting blindly and im- plicitly to the dicta of the botanist and chemist, and others whose acquain- tance with the actual cultivation of plants may be of the slightest. A man may be told that a certain soil contains enough plant food to last a thousand years, and an elaborate analysis of the phosphates, potash, iron, magnesia, soda, lime, and other essential plant foods will be produced in support of the statement. From a purely theoretical point of view such a statement may be chemically correct, but the said foods may be locked up or com- bined in such a way in the soil that it would take generations of hard work and a mint of money to bring them into anything like an available condition. While it would not be wise to ignore the chemical analysis of a soil altogether, the intelligent cultivator will not rely entirely upon it. He will use his own judgment, the value of which will of course depend largely upon his practical experience and observation. He will find a safer guide than mere chemical analysis in examining carefully the vege- tation of any piece of land he contemplates cultivating. Here his know- ledge of plants, their relationship to each other, and the natural conditions chat suit them will be of great value to him. " Nor every plant on every soil will grow : The Sallow loves the watery ground, and low ; The marshes, Alders : Nature seems to ordain The rocky cliff for the Wild Ash's reign ; The baleful Yew to northern blasts assigns, To shores the Myrtles, and to mounts the Vines." On poor, sandy, or gravelly soils, for instance, he will notice such plants 89 90 Commercial Gardening growing as the Lesser Bindweed (Convolvulus arvensis), the Musk Mallow (Malva moschata), the Hairy Cinquefoil (Potentilla argentea), the Gallic Catchfly (Silene gallica), the Speedwell (Veronica officinalis), the Hawk- weed (Hieracium Pilosella), Chamomile (Anthemis nobilis), Shepherd's Purse (Capsella Bursa-pastoris), Corn Bluebottle (Centaurea Cyanus), Poppy (Papaver Rhceas), Heather (Calluna vulgaris), Spanish Broom (Cytisus scoparius), Bracken (Pteris aquilina), Sterile Brome Grass (Bromus sterilis), &c. On wet or marshy soils the following weeds may be found: Dog's Bent Grass (Agrostis canina), Cuckoo Flower (Cardamine pratensis), Marsh Thistle (Cnicus palustris), Horsetail (Equisetum arvense), the Marsh Galium (Galium palustre), Corn Spurrey (Spergula arvensis), Comfrey (Symphytum officinale), Flowering Rush (Butomus umbellatus), Bulrush (Typha latifolia, T. angustifolia), Forget-me-Not (Myosotis palustris), Rushes (Juncus spp.), Sedges (Cyperus spp.), Loose-strife (Lythrum Sali- caria), Willow Herb (Epilobium), Common Carrot (Daucus Carota), Butterbur (Petasites vulgaris), Water Ragwort (Senecio aquaticus), Yellow Meadow Rue (Thalictrum flavum), Ivy-leaved Crowfoot (Ranun- culus hederaceus), Great Spearwort (Ranunculus Lingua), the Lesser Spearwort (R. Flammula), the Marsh Marigold (Caltha palustris), Water- cress (Nasturtium officinale), Sundew (Drosera), Mare's Tail (Hippuris vulgaris), Water Milfoil (Myriophyllum), Pennywort (Hydrocotyle vul- garis}, Water Parsnip (Sium), Valerian or All Heal (Valeriana), Bur Marigold (Bidens cernua), &c. On chalky or limestone soils: the Pasque Flower (Anemone Pulsatilla), the Stinking Hellebore or Setter Wort (Helleborus fostidus), the Baneberry or Herb Christopher (Actcea spicata), Whitlow Grass (Draba muralis), Penny Cress (Thlaspi perfoliatum), Cheddar Pink (Dianthus ccesius), Goldilocks (Aster Linosyris), the Fetid Hawk's Beard (Crepis fostida), Wild Sainfoin (Onobrychis sativa), Chicory (Cichorium Intybus), Fumi- tory (Fumaria officinalis), Bladder Campion (Silene inflata), &c. On clayey soil or very heavy loam will be found Docks (Rumex), Coltsfoot (Tussilago Farfara), Creeping Bent Grass (Agrostis repens), Floating Foxtail Grass (Alopecurus geniculatus), Sow Thistle (Sonchus arvensis), Rest Harrow Ononis spinosa. Where, however, one notices the Hawthorn hedges, Wild Plums and Sloes, the Elms, Oaks, Beeches, Ashes, and Lime trees growing luxuriantly, the soil bearing them, or adjacent, may be looked upon as the best for general gardening or farming. It contains a fair mixture of sand, clay, lime, and decayed organic matter (humus), and such a soil is likely to yield the best results if it is properly cultivated, but not otherwise. The following weeds also indicate a good loamy soil suitable for the cultivation of Fruits, Flowers, and Vegetables, viz.: Thistles, Stinging Nettles, Groundsel (Senecio vulgaris), Goosefoot or Fat Hen (Chenopodium album), Annual Sow Thistle (Sonchus oleraceus), Dandelion (Taraxacum officinale), Chick weed (Stellaria media), &c. The Science of the Soil 91 2. CLASSIFICATION OF SOILS Soils are classified in various ways, according to their texture and mechanical composition. Thus such terms as poor, hungry, cold, hot, wet, heavy, light, sour, sweet, are used to denote various conditions; while the terms sandy, clayey, loamy, chalky, marly, and peaty indicate the pre- dominating constituent of a particular soil. Several of these terms really mean the same thing to the cultivator. A poor, hungry, light, or hot soil, as a rule, indicates one of a sandy or gravelly nature. Such a soil is " poor " because it is impoverished of plant foods; it is "hungry" because it eats up enormous quantities of organic manures; it is "light", not because of its actual weight, but because it crumbles and falls to pieces easily, and its particles will not cohere and retain sufficient moisture or food; it is "hot" because its gritty particles absorb so much heat during the day that moisture is driven away from the roots of the crops. A " hot " soil also has great variations and fluctuations of temperature, being generally too hot by day in the summer and too cold by night in winter. A hot soil, however, that is well manured and supplied with sufficient moisture is valuable for the production of early crops. On the other hand, a cold, wet, heavy soil usually denotes one of an ill-tilled, clayey nature. Such a clayey soil is " cold " because of its "wetness", the heat of the sun being used to dry up the superfluous water instead of being available to warm the soil particles and promote root action. It thus follows that a wet and cold soil is also a "heavy" one, that is, one very difficult to lift, owing to the cohesiveness of its particles, and not so much on account of its actual weight. When a cold, wet, and heavy, clayey soil is also full of decaying organic material, and is never deeply cultivated, it then becomes "sour". This sourness is due to the fermentation and decomposition of the organic refuse, which liberates the carbonic acid gas so freely that oxygen is driven out of the soil. A good loamy soil even may be brought into a sour condition by overdressing with stable manure, and by not digging deeply to allow the fresher air to enter and the water to pass away freely to the lower strata. To test a soil for sourness or aciditjr, place a small portion into a clean Florence flask, adding enough distilled or filtered rain water to cover it. Boil over a lamp for about fifteen minutes, afterwards allowing the solid matters to settle. Then pour off the clear liquid, and test with a slip of blue litmus paper. If the paper turns red, it is a sign that the soil is sour. To remove the acidity, the soil should be deeply dug, and lime or basic slag added. It may be well to say something as to the peculiarities of sand, clay, loam, chalk, lime, peat, and humus. Sand. Sand consists of small pieces of hard rock that have been broken down into various degrees of fineness or coarseness from such Commercial Gardening rocks as silica or flint, sandstone, quartz, granite, &c., by the action of the weather and water. The peculiarities of sand are: it is hard and gritty; it will not float in water; its particles will not cohere readily even when wet, nor can they be moulded into any shape for any length of time; it will not hold water; it absorbs and radiates heat readily; and in a fine condition its particles are blown about easily by the wind when dry. When mixed with clay, peat, loam, and other soils sand is useful because it renders the soil more porous, warmer, easier to work, and better aerated all valuable properties for plant growth. Clay. This is also composed of fine particles, but much finer than in sand, and possessing different properties. The particles are soft and greasy to the touch when wet, and can be moulded into any form; they also float in water for a long time and make it " muddy "; they retain moisture for a long time, and will not allow it to escape readily. When dry, clay cracks and shrinks; when wet it expands, and becomes very slippery to the foot. Clayey soil by itself is fit only for making bricks, pottery, &c., the finest chinaware being made of a whitish clay containing silica, alumina, and water. When burned, clay undergoes marvellous changes. It is no longer sticky, plastic, or impervious to water, and its particles are loose, porous, and brittle. Even when wetted, burned clay can never revert to its original plastic and slippery condition. In some places the clay soil is often burned with the object of making it lighter, warmer, and more porous. The advantage of clay in a garden soil is that it detains moisture and manures, and prevents the temperature from rising too high in summer and from sinking too low in winter, owing to its poor conductive powers. Loam. Sand and clay in about equal proportions, and with a quantity of organic material, constitute a " loamy soil " the ideal soil for the hor- ticulturist or agriculturist. When a loamy soil contains more sand than clay it is called a " sandy loam "; when more clay than sand, a " clayey loam". The various compositions may be expressed as follows: Per Cent of Sand. Per Cent of Clay. Sandy soil contains ... 80 to 100 20 to Sandy loam 60 80 40 20 Loam 40 60 60 40 Clayey loam 20 40 80 60 Clayey soil 20 100 80 Chalk. A chalky soil is one derived from limestone rocks which, when burned, yield the lime of commerce. Lime differs from chalk in not con- taining carbonic acid gas; this was driven off in the burning. When lime is burned it is known as quicklime; and when water is poured on this it is readily absorbed, expansion takes place, and great heat is generated. The Science of the Soil 93 The result is then known as hydrate of lime. When quicklime is exposed for a time to the air, it gradually absorbs carbonic acid gas, and thus reverts to a chalky or carbonate of lime condition. Chalk or limestone (calcium carbonate) is known to geologists as organic rock, because it is made up of the remains of shells and bones of sea and freshwater fish. This may be seen by rubbing down some fragments in water and examining the dried sediment under the microscope. Minute shells, pieces of coral and sponges, and broken fragments of shells will be observed, as well as the remains of other marine creatures. Limestone hills and rocks are to be found in many parts of the world thousands of feet above sea level, and bear silent testimony to the upheavals that must have taken place on the surface of the globe in past ages. In the same way our coal seams represent ancient forests and fertile vegetation that have become submerged, and afterwards covered with deposits of other layers of soil. Lime. Lime, to use the popular term, is a most important ingredient in soils, and may be employed in various forms, such as marl, gypsum, quicklime, chalk, slaked lime, gas lime (or " blue billy "). For a heavy, wet, clayey soil a heavy dressing of quicklime is one of the ways of bringing it into a good state of cultivation. In milder forms of chalk (carbonate of lime) or gypsum (plaster of Paris) it is a valuable adjunct to good garden soils, especially if they have been overdressed with organic manures. The advantages of adding lime to the soil may be summed up as follows: 1. It makes a stiff or clayey soil drier and more porous by making the sticky particles coagulate or flocculate, and thus leave passages for the air. This may be proved by putting a little lime into a glass of muddy water. The particles that would otherwise float about for a long time soon come together in flocks and drop to the bottom, leaving the water clear. 2. Lime, being an alkali, is fatal to sourness and acidity in the soil, and renders it "sweet" and favourable to vegetation. Where magnesia is in excess the addition of lime will rectify any ill effects. 3. Without the presence of lime in the soil beneficial micro-organisms would not be generated from the organic constituents, and there would be a lack of nitrogenous food. On the other hand, when a soil has become too rich in nitrogenous foods, that cause luxuriant, sappy, and unproductive growths, the addition of lime will soon restore the balance, although at first giving apparently greater vigour to the shoots. The presence of lime in any soil may be detected in a simple way. Take a fair sample and place in a glass, and pour over it some fairly strong acid, such as hydrochloric. If lime is present a vigorous fizzing or effervescence will take place; if not, it may be assumed that little or no lime is present and it should be added. Peat. This name has been applied to the remains of plants that have accumulated in the course of centuries on the margins of shallow lakes and in marshy land. The lakes or marshes gradually disappear with the encroachment of the vegetation, and the latter becomes pressed down 94 Commercial Gardening into more or less solid or spongy fibrous layers of organic material often several feet deep. Wherever natural peat beds exist, they are found on soil or rock that has been hollowed out like a bowl or saucer into which the water from the surrounding land drains and keeps in wet condition for a great portion of the year. Peat when dry burns readily, and is used in the same way as coal in parts of Ireland and Great Britain. It absorbs water freely and is therefore valuable when mixed with sandy soil. Some plants, like Rhododendrons, Azaleas, Kalmias, Heaths, Andromedas, and many other Ericaceous plants like to have a good deal of peat in their compost; but very few plants would thrive in peat alone. Humus. While sand, clay, lime, and peat are all useful and necessary ingredients of every good garden soil, each one by itself would be practi- cally useless. When mixed together in certain proportions they are more valuable, but they still lack something to make them into a really good garden soil. It would be possible, for example, to obtain sand, clay, and limestone from the roadway when excavating for sewers and other pur- poses. But no one would dream of trying to grow plants upon such material, even if mixed in suitable proportions. There is evidently some- thing lacking, and that something is of an organic, not a mineral, nature. When the decayed remains of plants and the refuse from animals (including decayed leaves, peat, stable manure, &c.) are mixed with the mineral ingredients it is found that plants grow well. This plant and animal refuse in a thoroughly decomposed condition is known under the name of " humus". One of the most popular forms in which humus is added to the soil is leaf mould or leaf soil. Every crop would produce a large quantity of leaf mould every year, but much valuable material is wasted, and the deficiency must be made up by the purchase of stable and other manures. The best kind of leaf mould is seen in natural woods of oak, beech, lime, &c., more especially in the ditches and hollows where great accumu- lations have taken place. Leaf mould is largely used in the cultivation of many kinds of stove, greenhouse, and hardy plants mixed with loam, sand, and peat in various ways. The beds on which the French maraichers grow their Lettuces, Endives, Carrots, Radishes, Cauliflowers, &c. (see Vol. IV), are almost entirely humus, with a certain amount of inorganic gritty soil; hence the luxuriant and rapid growth that is secured. Advantages of Humus. The addition of humus to the soil has physical and chemical effects. Physically humus absorbs and detains moisture; it raises the temperature of the soil and maintains it in an equable condition; it keeps the particles of sand and clay asunder and therefore improves the aeration and porosity; it detains the heat, and thus prevents the roots of plants being frozen during hard frost. But humus performs other important functions in the soil, especially in con- nection with the nutrition of many trees and shrubs and green-leaved plants generally. It has been discovered that the roots of many plants The Science of the Soil 95 (e.g. Oaks, Beeches, Poplars, Elms, Rhododendrons, Cranberries, Bilberries, Brooms, Heaths, Conifers, &c.) are invested with the filaments of certain fungi, which, instead of being injurious, are actually beneficial. These fungal threads are interwoven in the tissues of the feeding roots, and often look like root hairs, and perform similar functions of absorbing water from the soil together with the mineral salts and other compounds dissolved in it. The name of " mycorniza" has been given to these fungi which envelop the roots of many plants, and it has been proved that they are not only beneficial and essential to the plants on which they grow, but that they can only come into existence when humus is present in the soil. This accounts for the great esteem in which all gardeners hold leaf mould Fig. 83. 1, Roots of White Poplar with inycelial mantle. 2, Tip of Root of Beech with closely adherent mycelial mantle x 100 (after Frank). 3, Section through a piece of wood of the White Poplar with the mycelium entering into the external cells, x 180. as an ingredient in the soils they use, and they know by actual experience that a soil without humus or leaf mould would be practically useless for their plants (fig. 83). Chemically, humus gives rise to living micro-organisms in the soil, when lime is present, during the process of fermentation and decay, if the temperature is favourable, .and thus yields up a supply of organic food in the process of decomposition. The following table shows the composition of three different kinds of humus: Constituents. Leaf Mould. Forest Mould. Peat Mould. Organic matter (humus) Clay and silica (sand) ... Nitrogen. per cent. 17-00 79-80 0-50 per cent. 8-46 63-34 0-45 per cent. 18-80 76-05 1-40 Potash 0-31 0-73 0-31 Phosphoric acid ... Lime 0-06 0-19 o-io 2-08 0-20 0-53 Magnesia Soda 1-71 o-io Monoxide 0-26 4-98 0-20 96 Commercial Gardening 3. MECHANICAL ANALYSIS OF SOILS Besides an examination of the natural vegetation referred to at p. 90 the experienced plant -grower will also make a physical or mechanical examination. He will handle the soil, feel its texture, noting its colour and whether its particles cleave together or fall asunder and crumble into dust; and if he is wise he will also have a good-sized hole dug out to a depth of 3 or 4 ft. so that he may see the geological formation. He will then be able to form a good opinion as to what may be done with the land. If the vertical section of the hole shows a good depth of yellow loam resting on sand, gravel, or chalk it is a good sign. Such a soil will contain plenty of plant food, may be easily, deeply, and economically worked, will not require large quantities of manures, will not be too dry or too hot in summer, nor too cold or too wet in winter, and will respond readily to good cultural practice. It follows that any other soil which does not approach this ideal is less valuable and may cost a good deal more to cultivate. To gain a fairly accurate idea as to the physical condition of a soil a fair sample of it should be taken from the first, the second, and the third spit down. A cubic foot of each might be taken and weighed. This multiplied by 43,560 will be the weight per acre. A certain quantity of soil, say 10 oz., should be spread out and allowed to dry in the sun and air. Weigh again, to see how much moisture has escaped, and com- pute the amount per acre. After air-drying and noting the amount of water given off, the samples should then be baked over a fire until all the organic material is driven off by combustion into the atmosphere. In this way the carbon, oxygen, hydrogen, and nitrogen will be liberated, and the residue will represent the mineral substances which cannot be further reduced. Then pass each sample through a sieve with an -in. or -in. mesh, so as to take out all the larger stones. Weigh these also and compute for the acre. The finer soil left should be mixed with water in a glass vessel and well churned up with a stick; hot water will free the finer particles better from the sand and gravel than cold. All the fine clayey particles will remain suspended in the water and make it muddy, while the sand and grit will fall to the bottom. By pouring off the muddy water time after time, until at last the water is quite clear, the mud or clay will be separated from the sand. Allow to settle, pour the water off carefully, and when sand and clay are dry they can be weighed. The result will show the proportion of each in the sample, and the weight may be computed for the acre. The weight of a cubic foot of soil of various kinds in a dry and wet state, and the amount of water each contains, have been computed >ias follows by M'Connell in his Notebook of Agricultural Facts and Figures: The Science of the Soil 97 Kind of Soil. One Cubic Foot Weighs. Amount of Water in One Cubic Foot of Wet Soil. In Air-dry State. In Wet State. Siliceous sand ... Ib. 111-3 Ib. 136-1 Ib. 27-3 Calcareous sand ... 113-6 141-3 31-8 Sandy clay Loamy clay Pure grey clay ... Humus ... 97-8 88-5 75-2 34-8 67-8 129-7 124-1 115-8 81-7 102-7 38-8 41-4 48-3 50-1 48-4 Garden mould ... The mechanical constitution of a good garden soil for the production of most fruits, flowers, and vegetables might be stated thus, and assum- ing that an acre of soil at 1 ft. deep weighs 3,000,000 Ib.: Clay, 40 per cent = 1,200,000 Ib. per acre. Sand, 35 = 1,050,000 Lime, 10 = 300,000 Humus, 15 = 450,000 These figures may be compared with the following analysis of a fertile soil on the same basis: Per Cent. Lb. per Acre of 3,000,000 Ib. Potash 1-03 30,000 Soda 1-97 60,000 06 1,800 Lime . ... ... ... ... 4-09 120,000 Magnesia 13 3,900 Peroxide of iron 9-04 270,000 Protoxide of iron 35 10,500 Protoxide of manganese Alumina 29 1-36 8,700 40,800 Phosphoric acid 47 14,100 Sulphuric acid 90 27,000 Carbonic acid... 6-08 180,000 Chlorine 1-24 37,500 Soluble silica ... 2-34 70,200 Insoluble silica clay \ Insoluble silica sand / Organic matter (humus) 57-65 12-00 1-00 1,729,520 360,000 30,000 The grower should avoid a purely sandy or gravelly soil, because it will empty his purse in purchasing manure and supplying water; and he should shun a wet, heavy, sticky yellow clay such as is suitable for the making of bricks and pottery, because it would require large funds VOL. I. 7 98 Commercial Gardening and many years of cultivation to induce such a soil to bear even reason- ably good crops. The very worst soils can be brought into a state of fertility in time, but it will never pay the commercial horticulturist to waste his time upon them. A man need not be a chemist to be able to distinguish the differences between a sandy, loamy, peaty, chalky, or clayey soil, and although each one contains essential plant foods in varying proportions it would be a mistake to assume that they are all equally valuable or available. These remarks relate chiefly to the soil when it is to be worked in a natural condition by the grower of fruits, flowers, and vegetables in the open air. Although the grower under glass is not hampered so much with the natural soil and the weather, it is nevertheless to his advantage O to select the best possible soil on which to erect his glasshouses, espe- cially if he intends to embark on the culture of such crops as Grapes, Tomatoes, Cucumbers, Peaches, Nectarines, or any other crop which is to root in the natural soil. For Melons, Ferns, Cyclamen, Chrysanthemums, Carnations, Bulbs, Zonal Pelargoniums, Heaths, Marguerites, Roses, and many other crops, soils have to be brought in and mixed in various proportions before use. The labour and expense of these operations are great, in addition to which large sums have to be spent on the erection of greenhouses and heating apparatus, the purchase of pots, &c. 4. HOW SOILS HAVE BEEN MADE It is from the sedimentary, organic, and igneous rocks that the farmer and gardener obtain the soil in which to grow their crops. When these rocks have been broken down into small particles and mixed in various propor- tions with organic material, they are capable of yielding up certain foods to plants with a proper supply of moisture and at a certain temperature. The various rocks have been converted into soil by natural and artificial agencies. Amongst natural agencies the most important are the gases of the atmosphere, water (including rain, rivers, streams), wind, heat and cold (frost and snow), and vegetation. Amongst what may be called artificial agencies are the cultural operations of man ploughing, digging, hoeing, harrowing, and manuring. The natural agencies may be embraced in one word, " weathering ", and the cultivator should impress upon his mind what important and powerful friends he has in them. The action of the weather rain, frost, snow, sun- shine, wind never ceases; it is wearing away the face of the hardest rocks and flints, as well as the surfaces of cultivated soils, both day and night, and bringing them into a more fertile condition. This important work costs nothing, but how many realize that it is always going on! It may be as well to consider the individual action of each of the natural agents. Water. Whenever rain falls it brings down a small quantity of The Science of the Soil 99 carbonic acid gas from the atmosphere with it. It falls on the earth and washes away fine particles from the hill and mountain sides into the plains and valleys. The mountain stream often becomes a torrent, and tears away great boulders, churning one against another, until they become rounded and worn away. The streams become rivers and eventually flow into the sea, and on their course they bring down masses of sand and silt, and deposit it in the lowlands. Many soils have been made in this way, and are said to be alluvial, because they have been washed on to a soil perhaps of a totally different nature. Running water not only performs this work, but also gradually dis solves particles of rocks into a fine powder and wears away the face ot them. This is called denudation. Water also fills the chinks and crevices in the rocks and carries out the same work slowly but surely. Being com- posed of the gases oxygen and hydrogen, and having a little carbonic acid in it, certain combinations with minerals and metals take place. What applies to rain and river water applies also to dew. If a piece of steel or iron is left in the open air for a night it soons turns rusty. This shows that the oxygen in the dew or rain has eaten into or combined with the steel or iron and produced rust. This eating away of metals by atmos- pheric gases is constantly going on, and in a few months a bright knife will be almost worn away by their action. Rain is not merely a combination of the gases oxygen and hydrogen; it also contains small quantities of nitrogen and ammonia, chlorine, and sulphuric acid. From the Rothamsted experiments it has been proved that from 3'30 Ib. to 4'84 Ib. of nitrogen and ammonia is distributed over an acre of ground during the year; and it sometimes happens that a small annual rainfall will produce a larger supply of these gases. Chlorine equal to 25'3 Ib. of common salt, and 17 '41 sulphuric acid per acre, have also been found in the annual rainfall at Rothamsted. Frost. This is a powerful agent in producing a powdery soil. When water in the soil or in the crevices of hard rocks becomes frozen, it swells up and occupies more space. In cultivated soils the particles are easily pushed asunder, and are often raised up a good deal. In the case of rocks the force exerted by the swelling ice is so tremendous that it is irresistible. The rocks are therefore forced apart, splitting along the line of least resist- ance, and when a thaw sets in great pieces are broken off. Fresh surfaces are thus exposed to the weather, and the process of disintegration goes steadily on. Heat. This has the effect of warming the soil, and water in it, causing both to expand and one of them (water) to evaporate. As water is driven out of the soil in this way air enters, and thus makes the soil warmer than it was before. As the temperature of the air varies greatly between mid- day and midnight, sometimes as much as 60 F., one can readily imagine a kind of opening and closing or expanding and contracting movement going on continually on the crust of the earth, much in the same way that the tides rise and fall, although not so conspicuous. This variation of IOO Commercial Gardening temperature has its effect in splitting up the soil into smaller particles. Of course the temperature varies according to altitude, season, and climate, but it seems to be universal that night temperatures are always lower than day temperatures. The temperature of the soil itself, as distinct from that of the air, varies according to the nature of the soil and the depth at which it is cultivated. All heat is derived from the sun, and the gardener seeks, in tem- perate climes at least, to secure as much as possible for his crops. Thus he likes to have his land with a gentle slope between the south-east and the south-west, because a larger surface is thus exposed to the direct rays of the sun. Even on level ground, if he is wise, he will always arrange his rows of fruit trees and bushes, Potatoes, Lettuces, Tomatoes, Peas, Beans, &c., running as near north and south as possible, so that the sun shall shine in be- tween the rows at midday to warm the soil about the roots. If the rows run east and west, one will shade the other, with the result that the soil will have a lower temperature, the effect of which is less feeding activity of the roots. The annexed diagram, from The Standard Cyclopcedia of Modern Agriculture, shows the variation of temperature in clayey, sandy, and chalky soils. It will be noticed in each case that the temperature of the soil at 4 ft. deep is always higher than that of the soil at 1 ft., and higher than the air, during the first three months of the year (January, February, March), and (in the case of clay and sand) during the last four months of the year (September, October, November, December). During the other months, April, May, June, July, August, the soil at 4 ft. deep is gener- ally several degrees cooler than the air. The diagram shows the variations for the three soils. Wind. This plays an important part in the formation of soils. It sweeps over the surface, taking away the moisture from it, and in dry Air Temperature Soil Temperature at I foot deep . Soil Temperature at 4 feet deep Fig. 84. Variation of Temperature in Clayey, Sandy, and Chalky Soils SALPIGLOSSIS (Three-fourths natural size) The Science of the Soil IOI weather the fine particles of dust and grit are borne from one place to another, together with leaves, twigs, and other organic material. Fresh surfaces are thus laid bare again for the action of rain, frost, snow, &c. Vegetation. It is thought that in the early stages of the earth's career only the lower forms of vegetable life could find a footing on its surface. The various Algae, Lichens, Mosses, were able to pick up a living at first. In due course they died, and their remains mingled with the surface soil, thus gradually bringing about a compost suitable for the growth of higher plants " Dissolve to dust and make a way For bolder foliage nursed by their decay ". And so on, from one stage to another, one class of plants succeeding another, and some even being crushed out of existence altogether, as we learn from the fossil remains found in coal seams, shale, &c. Animals, when they came, helped also to make our soils, and, like the primitive plants, many of these died out under the stress of competition from newer races. Worms also play an important part in the ventilation of the soil, and wherever very large numbers are present it may be taken as a sign that the subsoil is in a wet and heavy condition, and should be trenched or at least double dug. These natural soil-forming agencies, although of the greatest importance, are nevertheless too slow for horticultural and agricultural purposes. If a farmer or a gardener waited until the rain, frost, snow, heat, cold, and wind, fec., converted a heavy clay soil into a fertile condition, he and his race would soon become extinct. He therefore hastens the process of dis- integrating various rocks and soils by such cultural operations as ploughing, digging, trenching, manuring, &c. He " tills " the ground, and by ever exposing fresh surfaces to the natural agencies of the weather, he, more or less quickly, brings the soil into a condition capable of bearing large crops of cereals, fruits, flowers, and vegetables. This condition is known as fertile, whereas a soil that will not respond to such operations is known as sterile. 5. CULTURAL OPERATIONS Ploughing*. Although regarded as being almost entirely an agricul- tural operation, many market gardeners also adopt this method of breaking up their open land, and often even use the plough between fruit trees and bushes when space permits. Ploughing itself requires a good deal of skill on the part of the work- man. A good ploughman will not only adjust the implement in such a way as to place as little strain as possible upon his horses, but he will also per- form more good work in a given time than an unskilled or slovenly worker. In ploughing, the surface soil only is broken up to a depth of 6 in. or 8 in., the width of each furrow being about 10 in. on an average. The cost of ploughing an acre of ground is about 15s., but it may be more or 102 Commercial Gardening less according to the nature of the soil. From 1 to 1| ac. can be ploughed in a day, and it is this facility for turning over the ground quickly that has made ploughing more popular than spade cultivation. When the ground is "subsoiled" a subsoil plough follows the other in the trench and moves the lower soil to a depth of 15 to 18 in. The cost of subsoiling 1 ac. of land would be about the same as for ploughing, thus making the total cost per acre for the two operations from 80s. to 40s. There are many kinds of ploughs now in use, but all have the same object in view, namely, to turn the soil up as well and as quickly as possible at the least expense. One of the latest inventions is an electric plough, invented by Mr. E. O. Walker of Manchester. This is intended to supersede the steam plough, wherever electric power can be procured easily and cheaply. Electric wires overhead are used for a trolley as in tramcars, and the plough is hauled across the field from one side to another as in the case of steam ploughs. The same principles of shallow ploughing are adopted, but if Fig. 85. iHagram showing Water (W) standing between Ridges in Land ploughed 6 in. deep electricity or steam could be harnessed in such a way as to turn the soil over to a depth of two or three feet, it would make a vast difference to the fertility of the soil in the course of a year or two. The great disadvantage of ploughing is that the soil is not turned over to a great depth, and a hard pan is formed beneath the loosened layer. In some soils this pan is so hard that it is impossible for air or rain to enter the subsoil; and it is just as difficult, for the same reason, for the tender rootlets of the plant to extend their search for food. All the fertilizing advantages to be derived from the drying and warming action of the air, the solvent effects of the rain, and the penetrating power of the roots are thus rendered abortive, or at least greatly reduced. The diagram (fig. 85) shows how the water after a heavy rain remains on the surface between the ridges in ploughed land, until it is evaporated by the heat of the atmos- phere and the wind. Under such circumstances the soil is cold and wet, and cannot be worked, while the beneficial bacteria cannot come into being in the soil until warmer and drier conditions prevail. The hard pan brought about by repeated ploughings has been recognized as such an evil by some American farmers, that they have taken the heroic measure of breaking the subsoil up by charges of dynamite. Digging. This operation is done with the spade or the fork. It is a much better way of turning up the soil than with the plough. Not only does the spade or fork go deeper, but the soil is turned over more com- pletely, and the clods are broken down into much finer particles. An expert workman will dig from 8 to 15 rods (about 240 to 450 sq. yd.) The Science of the Soil 103 in a day, according to the nature of the soil. The cost of digging 1 ac. of ground 1 ft. deep will vary from 40s. to 55s., more or less according to the state of the soil and the rate of wages in different parts of the Kingdom; and it will take one man from eleven to twenty days to perform the work properly, and turning over from 70 to 120 tons of soil each day. Digging consists in opening a trench one spit deep, the full depth of the spade or the fork, and filling it with soil adjacent after lifting and turning completely upside down. Double Digging 1 . Double digging consists in opening a trench twice as wide as in ordinary digging, and after the top spit has been removed, the bottom is then broken up but usually left in the same position. Manure is then added before the soil from the next top spit is placed on it. Considering the depth of soil moved, the better breaking up of the particles, and the enhanced fertility, it is a question if digging is not on the whole a more economic method of cultivation than ploughing. One acre of dug ground will produce better and more saleable crops than 1 ac. of ploughed ground of a similar nature. The extra cost of digging is there- fore more than repaid by the increased yield and value; in addition to which must be reckoned the saving of half an acre's rent, the saving in gathering the crop over a smaller area, and the saving in subsequent culti- vation. This proposition may appear more feasible if stated in figures. If an acre of ground dug by the spade or fork is only equivalent in yield to 1| ac. of ploughed land, one may take the ratio on a larger scale, as follows: 120 ac. ploughed Rent at 2 per acre = 240 Ploughing at 15s. per acre = 90 330 80 ac. dug. Rent at 2 per acre = 160 Digging at <2 per acre = 160 320 It is evident that if a man can get as much produce off 80 ac. as he can off 120 ac., by a superior method of cultivation, he will be wise in adopting the superior method. He will employ far more labour, and he will be keeping men and their families on the land instead of keeping ploughs rusting in his barns. The question of labour and its arrangement of course requires careful consideration, so that the employees shall have work all the year round at a regular wage; but this is merely a matter of organization. The point for the commercial grower to consider is whether it will pay him better to spend say 330 per annum in half -cultivating 120 ac. of land, or whether it is more to his interest to spend 320 ten pounds less in properly cultivating 80 ac. and reaping better results. What is known as "bastard trenching" is taking out one spit of soil, and then taking up the loose soil or " crumb " at the bottom and spreading it over the top. Work like this will cost about 6d. per rod, i.e. 4 per acre. Trenching". This operation can only be carried out where there is a good depth of soil. Hence in hilly or mountainous districts, where only IO4 Commercial Gardening a few inches of soil rest on hard rock beneath, trenching and even double digging is often out of the question. When trenching ground, the soil is marked out in strips about 3 ft. wide, and the first trench is taken out to a similar depth. Before the soil adjacent is thrown into the trench in front it is a good plan to place a good layer of weeds, green vegetable refuse, twigs, &c. in fact all coarse and untidy vegetation at hand in the bottom. The only refuse to avoid putting in the trenches is Potato haulms and the clubbed roots of cabbage crops. These should be always burned to destroy the spores of the terrible diseases which often afflict them. Having prepared the first trench in the way indicated, the next piece of ground is marked off 3 ft. wide, and the soil from this, spit by spit and layer by layer, is placed in the trench, until this is of course filled up, and a new trench is along- VII VIII IX ''////////////////MM IV VI III IV VII VIII VI IX AC B Fig. 86. Diagram showiug how ground may be trenched 3 ft. deep, bringing the bottom layer to the top to be fertilized by the weather, and to allow the free passage of air, rain, and roots downwards. Shaded portions indicate layers of manure. Note how trenched soil A is raised higher than the un- trenched B. shows how soil has been dug out and placed at A. In B the figures 1 to 9 show how the soil is to fill the trench in the same way as at A. side. Where plenty of refuse and manure are available it will pay to place a layer between the spits, keeping the best and most rotted manure for placing beneath the top spit. A kind of sandwich of soil and manure will thus be formed, as shown in the diagram (fig. 86). Very few, if any, commercial gardeners adopt this system of culti- vation, partly because of the cost of labour and manure, and partly because they fear that it would be one of the greatest mistakes possible to bring up the subsoil from a depth of 3 ft., and place it on the surface, especially if it happens to be of a clayey, sticky nature, or of gravel. But it would be well to remember the words of Virgil: " Well must the ground be digged and better dressed New soil to make, and meliorate the rest". One can appreciate the argument against trenching on the score of ex- pense; but if it is going to be done there will be no more, or very little more, expense or labour attached to bringing up the bottom spit and exposing it to all the fertilizing influences of the weather. As a rule this is the case. There is only one possible danger, and that is if the subsoil should contain a large proportion of ferrous oxide or protoxide The Science of the Soil 105 of iron. This is distinctly unfavourable to plant growth, and is often met with in yellow clay soil; but, as already stated at p. 97, it would be foolish to choose a soil of this nature in the first place. This poisonous ferrous oxide must not be confused with ferric oxide or peroxide of iron, which is a valuable constituent of the soil. It promotes vegetation and the development of the green colouring matter in leaves, and performs other useful functions. Even if one is so unfortunate as to have a soil containing much poison- ous ferrous oxide, the best way to remedy this defect is by bringing up the bottom soil and exposing it to the action of the weather. One of the most important changes that takes place is the absorption of oxygen from the air by the ferrous oxide, W n > 1 I which in the course of time be- comes converted into the useful and fertilizing ferric oxide. The cost of trenching soil to a depth of 3 ft. will vary from 8 to 12 per acre, an appalling item apparently to a man with limited capital; and then manur- ing, hoeing, &c., must be added, so that the cost of deep cultiva- tion may well average 9 or 10 per annum per acre if vegetable crops only are to be grown. Against this great expense, how- ever, must be placed the follow- ing advantages: (1) An abundance of available plant food; (2) earlier, heavier, and more remunerative crops; (3) abundance of warmth and moisture at the roots in the hottest of summers; (4) lack of insect pests and fungoid diseases; (5) saving in insecticides and fungicides; and (6) an absence of weedy vegetation and a consequent saving in plant food. If it is intended to grow fruit trees and bushes, it would be even more wise to trench the soil to a good depth at first before planting, because once fruit trees are planted it will be afterwards almost impossible to rectify any troubles in the soil without incurring great expense. To bring soil into a proper condition for fruit culture, it may be advisable to crop it with Potatoes, Cabbage crops, Jerusalem Artichokes, Celery, Parsnips, &c., the roots of which would penetrate the soil deeply and break it into finer particles. When digging, double digging, or trenching, it will be found convenient to divide the ground into convenient portions, as shown at a, b, c, d (fig. 87). By dividing each portion, as shown at ef. into two sections, a good deal of labour and wheeling will be saved. The soil from the first trench, 6 to /, when taken out, may be placed in front of the section efcd at fd When the work has reached ae, the trench there is to be filled with soil Fig. 87. Diagram showing how the Ground may be marked out for Digging or Trenching io6 Commercial Gardening taken from e to c. The work then proceeds to fd, and the soil which has been wheeled there from bf is used to fill the last trench. Ridging 1 Up. This is an excellent cultural operation, and is almost equal in value to double digging. By digging a piece of ground length- ways, the soil from the trench is placed on the adjoining soil to the right or left, thus forming a ridge about 2 ft. high on one side and a trench correspondingly deep on the other. If the base of the ridge be 2 ft. wide, soil to cover one-half of it is taken from one side, and to cover the other half from the other side. In this way heavy soil is brought up, and a large surface is exposed to the weather. The soil in the bottom of the trenches on each side of the ridges may be still further improved by breaking up with the fork. A modification of ridging is to turn up a " spit " of soil and invert it in same place. The next spit is taken up and placed on top of the first, thus making a hillock and hollow alternately. Soil that has been ridged up in winter will be beautifully sweet and mellow in spring, when the crests of the ridges may be easily levelled down with a fork before sowing or planting operations. Raking* and Harrowing*. The rake is to the horticulturist what the harrow is to the agriculturist. They both have the same object in view namely, to level the surface of the ground, and break the clods into powder so that it may be easier and better for the sowing of seeds. The rake is useful for small areas, but the harrow (of which there are several varieties) is adapted for drawing over large areas. The heavier harrows are useful in clearing off the weeds, as are also the chain harrows, while the lighter ones are used in connection with seed sowing. Rolling*. This is also a horticultural and agricultural operation. Its object is to crush the clods still further, to make the surface more level, and to compress the particles sufficiently to hold moisture and make a firm root run. It would be fatal to growth to have large fissures in the soil, or to have it so loose and spongy that tiny seeds would sink down so deeply that the seedlings would never be able to reach the light. Rolling ground, or treading on it with the feet, therefore, has the effect of packing the soil particles together, without making them adhere so closely as to prevent the entrance of air and water. Hoeing*. The hoe does not receive from the farmer or gardener the respect to which it is entitled. It is kept lying idle very often until the land becomes foul with weeds that have robbed the land of much of its food and moisture (see p. 116) that will cost more to replace than half a dozen hoeings. The hoe should be in constant use while the crops are growing. It is invaluable as a food producer, a weed killer, and a moisture conserver, and when used with regularity the cost of hoeing an acre of ground, even by hand, is not great, perhaps 8s. to 10s. or 12s. at the most. When the soil has become overrun with coarse weeds, and the surface is also baked, the cost of hoeing an acre may be anything from 20.9. to 30.s\ The material advantages to be derived from regular hoeing are: The Science of the Soil 107 1. The upper crust is kept in a finely powdered condition. 2. Weeds are unable to grow and rob the soil of food and water, nor the air of carbonic acid gas. 3. By pulverizing the soil, fresh mineral foods are liberated for the roots by the action of the weather. 4. In hot seasons the freshly moved soil acts as a mulching and prevents the moisture escaping (see p. 123). 5. The dews are absorbed at night and are soaked down to the upper rootlets with fresh food. 6. The use of the hoe, especially during the summer months, prevents many insect pests from nesting in the soil, and the chrysalides of others are brought to the surface for the benefit of the birds. 7. As large supplies of food are liberated by the hoe, there should be a corresponding saving in the chemical manure bill, and as water is conserved, there is not only a better crop, but it also comes to maturity more quickly owing to the accelerated growth. Taking these advantages into consideration it would pay every market gardener to keep his ground regularly hoed from February or March to October, and the money spent on it would be refunded over and over again. 6. THE BEST TIME TO WORK THE SOIL Whether the soil is to be ploughed, dug, or trenched in spring or autumn will depend largely upon its nature. Generally speaking it is better to turn up heavy soils in the autumn and light soils in the spring. As heavy soils contain a larger amount of dormant food than light soils, and as it takes longer to transform them into a soluble condition, it is better to have them ploughed, dug, or trenched during the autumn and winter months. Fresh surfaces are thus exposed to the action of the weather; clods are crumbled down into powdery masses by the action of frost, rain, snow, wind, &c.; the air enters more freely between the particles, and sourness and acidity are driven out by the sweetening action of the atmospheric oxygen. The soil thus becomes "sweeter"; it also becomes warmer, because better drained, and owing to the action of the carbonic acid in the air, and arising from decomposing manure, supplies of potash, phosphoric acid, nitrates, and other valuable foods become available by spring. At this period also the over-harsh clods are easily broken down by the rake or harrow, and can be rendered sufficiently fine for the reception of seeds of various crops. If "light" land is ploughed, dug, or trenched in autumn precisely the same beneficial results would follow, but much more quickly. This would be a distinct disadvantage to the farmer and gardener at this season. Having no growing crops on the land to take up the freshly liberated food, there is a danger that this would be washed down into the lower layers out of reach of the roots. Thus, when sowing and planting time arrived in spring, although the soil would be easily worked, it is possible that the upper layer would be much poorer in plant food than it was before the autumn breaking up. io8 Commercial Gardening The cultivator therefore must always pay attention to the physical or mechanical condition of his soil rather than to its chemical composition, and he must regulate his operations accordingly. It may be stated as a good general rule, that whenever a crop is ready to be placed on the soil, it is a good plan to have it dug in advance whether it be spring, summer, or autumn. 7. PLANT FOODS IN THE SOIL AND AIR By means of experiment it has been proved that all green-leaved plants at least require certain essential foods to enable them to perform their functions properly. Some of these foods are absorbed from the air under the influence of sunlight, and some are taken from the soil by the roots. These essential foods are Nitrogen . Potash Iron Phosphorus Lime Soda Sulphur Magnesia Chlorine Silica. These thirteen foods are found in all plants in varying proportions. The first four are gaseous and organic, and are driven from the plant by burning. The other nine are found in the ash of plants, and constitute the mineral or inorganic foods. When soluble in water, they are in a condition to be absorbed from the soil under favourable conditions. Until about three hundred years ago it had been always thought that the soil supplied all the foods of plants and made up the great bulk of the tissues. Jean Baptiste van Helmont (b. 1577, d. 1644), a chemist of Brussels, was the first to disprove the old theory that all plant foods came from the soil alone. He planted a young Willow weighing 5 Ib. in a pot containing 200 Ib. of soil. He watered the plant daily with rainwater, and grew it for five years. He then weighed the plant and soil again and found that the Willow had increased from 5 Ib. to 169 Ib., but the 200 Ib. of soil had lost only about 2 oz. Van Helmont therefore concluded that the extra 164 Ib. weight of the Willow came from the water alone. In this he was wrong. He did not know that the invisible carbon in the air had anything to do with the increased weight of his W T illow. Indeed it was not until a Dutch scientist, Jan van Ingenhuisz, published his researches in 1779 that it was discovered that the increase in weight was due to the carbon that had been assimilated from the atmosphere by the leaves during the daytime (see p. 44). It is evident, therefore, that only a very small proportion of plant food is actually taken from the soil itself. That little, however, is absolutely essential; and unless it is in a form easily dissolved in water, so that it may be absorbed by the roots, it is quite useless, and no growth can take place. The figures on p. 109, compiled chiefly from Dr. A. B. Griffith's works, The Science of the Soil 109 FRUIT CROPS ASH ANALYSES Name of Crop. Potash. Phosphoric Acid. 35 | 3 H . 3 T3 H 05 1 *J Magnesia. 3 o 02 Chlorine. 4 ^ o5 Apple, wood ... 19-24 4-90 63-60 0-93 1-66 7-46 0-45 0-45 1-31 Apple, fruit ... 56-21 10-89 4-87 3-05 1-93 6-53 14-02 0-68 2-82 Pear, wood 55-00 13-93 7-99 5-73 1-20 5-42 8-69 0-52 1-52 Plum, wood ... 56-99 12-09 6-39 3-33 5-21 9-25 5-24 0-20 1-30 Cherry, wood ... 21-63 7-56 30-24 2-62 2-62 8-72 1-84 0-81 24-96 Cherry, fruit ... 51-37 14-62 7-64 5-03 3-21 5-28 1-14 2-10 9-61 Peach, wood ... 52-61 13-69 4-88 3-21 1-20 4-10 11-89 0-55 7-71 Apricot, wood... 54-88 13-86 3-52 2-95 1-71 3-85 10-57 0-60 7-85 Apricot, fruit ... 60-20 12-00 4-26 3-06 1-26 2-12 9-68 0-45 6-91 Greengage, wood 58-09 13-99 9-81 3-62 5-00 6-28 0-12 0-61 2-48 Strawberry 41-40 11-70 12-21 3-15 11-14 2-93 1-29 2-78 12-05 Tomato, plant... 27-00 18-28 12-10 4-86 3-96 8-21 10-39 2-54 12-36 Tomato, fruit ... 53-04 14-53 4-38 0-92 3-97 Cucumber, plant 39-34 19-66 6-57 6-5(5 1-40 3-28 9 : 83 6-56 8-20 Cucumber, fruit 51-71 13-10 6-98 5-70 0-75 4-50 4-19 9-66 3-41 Grape vine 37-48 9-20 43-88 3-61 1-08 1-05 1-33 1-65 0-72 Gooseberry 38-65 19-68 12-20 5-89 4-56 5-85 9-92 2-58 Damson 45-98 13-83 12-65 2-37 1-19 8-17 5-66 9-22 Fig 28-36 1-30 18-91 6-75 1-46 9-21 26-27 5-93 VEGETABLE CROPS ASH ANALYSES Name of Crop. Potash. Phosphoric Acid. 03 e 21 o id fl 2 || *j .4 55 CD I 4 3 GO Chlorine. J cc Cabbage 31-95 12-93 15-66 8-61 8-32 4-93 2-51 7-99 4-99 Cauliflower . . . 34-39 25-84 3-07 11-16 3-67 2-38 14-79 2-78 1-92 Turnip 50-12 16-41 13-02 6-95 0-32 2-00 3-62 6-32 1-21 Kohl-rabi 48-69 16-75 13-65 6-82 0-48 3-18 3-89 5-31 1-23 Radish 23-65 40-12 8-92 6-97 2-10 3-64 3-01 3-59 8-00 Peas ... 20-10 40-10 6-90 2-00 1-40 8-90 17-30 1-20 2-10 Beans 42-50 34-66 6-00 3-50 0-40 7-30 3-34 1-40 0-90 Carrots 48-20 18-43 13-86 6-30 0-35 3-71 2-68 5-21 1-24 Parsnips 47-10 19-25 14-62 7-21 0-40 3-63 2-00 4-10 1-66 Celery 22-07 11-58 5-58 2-66 5-82 3-85 Beetroot 49-11 15-26 8 : 82 7-00 0-22 7-23 4-83 6-18 1-33 Lettuce 46-26 8-21 6-24 5-36 0-21 2-15 6-08 5-49 20-00 Endive 37-62 3-21 12-02 5-92 0-29 2-13 11-00 2-03 24-78 Rhubarb 30-00 18-13 14-21 5-04 3-68 7-33 9-78 2-03 8-06 Onion 32-35 15-09 13-66 8-34 12-29 2-70 8-04 4-49 3-04 Asparagus . . . 6-01 18-51 4-39 4-13 3-31 3-03 34-21 12-94 13-47 Jerusalem ^ Artichoke ) '" 44-62 14-97 8-36 5-21 4-31 6-89 9-63 2-98 13-03 Potato, tubers 55-75 12-57 2-07 10-62 0-52 5-28 1-86 7-10 4-23 io Commercial Gardening will give some idea as to the various mineral foods taken out of the soil by different fruit and vegetable crops. These foods must be all soluble in water, and the temperature of the soil must be favourable, otherwise the roots would be unable to absorb them. It will be noticed that the same food is taken up by different crops in different proportions, and there is often a great difference in the composition of the wood and the fruit on the same plant. It should also be stated that the results obtained by different chemists vary greatly, probably owing to the plants tested being taken from different soils and at different times. The quantity of these foods to an acre may be seen from the follow- ing analysis of Broadbalk Field, Rothamsted. The soil had not been manured for fiity years, and at 9 in. deep the weight of an acre was 2,500,000 Ib. containing Carbon ............ 22,250 Ib. Nitrogen ...... ... 2,500 Soda ............ 1,500 Potash ............ 6,750 Magnesia ......... 9,000 Lime ............ 62,250 Alumina ......... 112,250 Oxide of iron ......... 85,000 Phosphoric acid ... ... 2,750 Sulphuric acid ... ... ... 1,250 Carbonic acid ... ... ... 32,500 Total ... 338,000 This particular soil lost about 4'20 per cent, or 105,000 Ib., on ignition; 12'53 per cent, or 313,250 Ib., was soluble in hydrochloric acid; and the undissolved siliceous matters were 83'27 per cent, or 2,081,750 Ib. These figures would indicate that there is an inexhaustible supply of food in the soil far more than could be absorbed by many crops in the course of several years. It has been estimated that an acre of fruit trees would require each year about 200 Ib. lime, 150 Ib. potash, 75 Ib. nitrates, 50 Ib. phosphoric acid. It would thus take over 311 years to exhaust all the lime in the Broadbalk Field at Rothamsted, 45 years to exhaust all the potash, 33 years to exhaust all the nitrogen, and 55 years to exhaust all the phos- phoric acid. And it must be remembered that these quantities are given for an acre of ground unmanured for 50 years, and taken from only 9 in. deep. In an American experiment, soil at 1 ft. deep (not 9 in.) gave 3,225,000 Ib. weight to the acre, and was estimated to contain Phosphoric acid ... ... 6,772 Ib. per acre. Potash I... ....... 32,897 Lime ......... ... 47,407 The Science of the Soil m An average of the results of forty-nine analyses of typical soils in America showed that the first 8 in. of surface soil contained Nitrogen 2,600 Ib. per acre. Phosphoric acid ... ... 4,800 Potash 13,400 In a good Hertfordshire soil analysed by Dr. Voelcker the following quantities of plant foods were found: Phosphoric acid ... 4,569 Ib. per acre (over 2 tons). Potash 10,483 ( 5 ). Lime 74,188 ( 33 ). Magnesia ... ... 9,676 ( 4 ,. ). Sulphuric acid ... 4,569 ( 2 ). Nitric acid ... ... 22 Nitrogen 2,397 ( 1 ton). The surface soil from 9 to 12 in. deep is usually regarded as being more fertile than the subsoil beneath. Although farmers may accept this statement, many modern gardeners question it, for experience proves that by turning the soil over to a depth of 2, 3, and even 4 ft. mag- nificent crops can be secured. Indeed this has been proved for centuries by Chinese and Japanese gardeners, who are adepts at deep cultivation. Of course if the upper 9 or 12 in. of soil only are cultivated and man- ured it is possible to prove that it is richer in available plant food than the layers of soil immediately beneath. But actual practice proves that if the subsoil is also cultivated and manured, and brought up to be acted upon by the weather, it will gradually yield up the foods it contains. The following comparison between the plant foods in the soil and subsoil is worth consideration: Subsoil. 53-71 per cent. 3-96 3-27 7-15 8-85 0-21 1-02 1-89 10-36 0-49 0-94 1-32 6-83 Surface Soil. Silica, insoluble .. Silica, soluble Alumina ... Iron Lime 59-26 per cent 2-63 3-12 6-10 5-36 Magnesia... Soda 0-02 0-93 Potash 1-53 Carbonic acid 7-00 Phosphoric acid ... Sulphuric acid ... Chlorine ... 0-13 0-63 1-20 Organic matter ... 12-09 100-00 100-00 With the exception of organic matter (which can be easily supplied U2 Commercial Gardening by means of stable manure and other vegetable and animal refuse) these figures indicate that the subsoil really contains, on the whole, a larger supply of plant food than the upper crust. Owing to the fact that the latter is usually the only portion cropped it is not unnatural that it should lose some of its available food and thus become poorer. Thus one hears of a soil becoming "exhausted", by which is meant that it no longer yields the same quantity of good saleable produce as formerly, notwithstanding the fact that it has been cultivated and manured. The " top spit", which is therefore usually regarded as the best soil, may be really in a worse and poorer condition than the soil beneath it, owing to constant cropping, and because it is "always carefully kept on top". If any reliance at all is to be placed on the figures quoted above from Dr. Voelcker and others, it is palpable that there is an enormous supply of plant food locked up in the earth, and if it can only be made avail- able not all at once, which would be fatal, but gradually the culti- vator has but to work his soil properly to liberate this food. But this is just where the chemical theorist fails and where the culti- vator comes in. Jethro Tull and the author of the Lois Weedon System of Cultivation were misled like many others with figures showing the abundance of food contained in their soils, but in practice they failed to obtain the best results. They practised deep cultivation, but they overlooked the fact that something besides a good supply of mineral food was also necessary. They overlooked the important factor of organic or stable manure and humus generally. It is as true now as in the days of Adam, notwithstanding our advance in the science of agricultural chemistry, that the gardener or the farmer who would reap the best results from his land must not only cultivate deeply, but he must also " load his fallow ground with fattening dung". 8. HOW TO EXTRACT PLANT FOODS FROM THE SOIL Assuming that the soil contains the food supplies already tabulated, the only way to bring them within the reach of any crop is by a rational system of supplying organic manures (see p. 145) and by deep cultiva- tion. This is apparently a costly method, but it is really more economic than the prevailing system, as we shall endeavour to prove. In these days there is a good deal too much quackery about supplying foods to plants in a chemical and more or less unnatural form. Growers are told they have only to give their soil a dressing of this, that, or the other special manure, and their crops will be increased a hundredfold. There is never a suggestion of cultivating the soil deeply (that would sound too laborious), and the natural condition of the soil itself is rarely taken into account; whether it be clay, sand, loam, or gravel the same manures are recommended in all cases and under all circumstances. The result The Science of the Soil in many cases is that the grower spends his money uselessly and thought- lessly, and his crops are a failure instead of a success. Here and there, where the special manure happens by accident to suit the soil, good results are secured. The grower is delighted. He pins his faith to that particular brand, and uses it exclusively, until at length he finds that he has ruined his soil and lost his money. This system of cultivation is on a par with the methods of a man who seeks to keep himself in good health by the aid of somebody's much-advertised pills, without taking sufficient natural food or exercise. Sooner or later he becomes a physical wreck (like the soil), and the pills (like the chemical manures) no longer perform the miracles in his system they did when first used. This view is borne out in a striking manner from the experiments on Wheat at Rothamsted, an account of which has been published by Mr. A. D. Hall in The Book of the Rothamsted Experiments, from which the following figures are taken: TABLE SHOWING THE AVERAGE PRODUCE OF GRAIN PER ACRE THE FIRST EIGHT YEARS (1844-51), AND OVER THE SUCCESSIVE TEN-YEAR PERIODS Plot. Manures Applied. 8 Yrs., 1844-51. A 10 Yrs., 1852-61. rerages in 10 Yrs., 1862-71. Bushels 10 Yrs., 1872-81. af Grain c 10 Yrs., 1882-91. ver 10 Yrs., 1892-901. 50 Yrs., 1852-901. 2 Farmyard Manure 28 34-2 37-5 28-7 38-2 39-2 35-6 3 Unmanured 17-2 15-9 14-5 10-4 12-6 12-3 13-1 5 Minerals 18-4 15-5 12-1 13-8 14-8 14-9 < Single Ammonium Salts and\ Minerals / 27-2 25-7 19-1 24-5 23-1 23-9 '{ Double Ammonium Salts and") Minerals ... ... / 347 35-9 26-9 35-0 31-8 32-9 < Treble Ammonium Salts and ) Minerals ... ... / 36-1 40-5 31-2 38-4 38-5 36-9 10 Double Ammonium Salts alone 25-1 23-2 25-1 17-3 19-4 18-4 20-7 { Double Ammonium Salts and \ Superphosphate ... / 28-4 27-9 21-7 22-7 19-5 24-0 { Double Ammonium Salts and I Sulphate of Soda ... / 33-4 34-3 25-1 30-1 26-7 29-9 u( Double Ammonium Salts and ) Sulphate of Potash ... / 32-9 34-8 26-8 32-5 29-6 31-3 ,4{ Double Ammonium Salts and } Sulphate of Magnesia / 33-5 34-4 26-4 31-1 25-0 30-1 i From these figures it will be seen that, while the yield per acre from farmyard manure steadily increased, except in one decade (1872-81), from 28 bus. of grain per acre to 39'2 bus., in every case of chemical manures except the " treble ammonium salts and minerals " there was a conspicuous and remarkable decline in the yield. All plots show a big drop for the decade 1872-81, "a period of notoriously bad seasons", as Mr. Hall states. A recovery then took place, but it was as marked in the "unmanured" plot, No. 3, as in some of the others. Indeed the unmanured plot re- covered more effectually than did Plots 5, 10, and 11. Comparing the aver- age yields over the period specified, it will be noticed that while farmyard manure shows an increase from 28 bus. in 1844 to 39 bus. in 1901, all the VOL. I. 8 Commercial Gardening others show a decrease, with the exception of the plot that had been man- ured by "treble ammonium salts and minerals". The drop in yield is so remarkable that it is worth while to state it in tabular form, thus: Plot 2. Plot 3. Plot 5. Plot 6. Plot 7. Plot 8. Plot 10. Plot 11. Plot 12. Plot 13. Plot 14. 1st Year 50th Year . . . + Increase or) Decrease / bus. 28-0 39-2 bus. 17-2 12-3 bus. 18-4 14-8 bus. 27-2 23-1 bus. 34-7 31-8 bus. 36-1 38-5 bus. 25-1 18-4 bus. 28-4 19-5 bus. 33-4 26-7 bus. 32-9 29-6 bus. 33-5 25-0 + 11-2 -4-9 -3-6 -4-1 -2-9 +2-4 -6-7 -8-9 -6-7 -3-3 -8-5 In Plots 2, 3, and 10 the experiments commenced in 1844; all the others commenced in 1852. Plot 2 received farmyard manure, and shows an in- creased yield of 11 '2 bus. per acre. Plot 3 was "unmanured", and at the end of fifty-eight years shows a decline of 4'9 bus. per acre. It will be noticed, however, that this decline is greatly exceeded in the chemically manured Plots 10, 11, 12, and 14, which show a drop of 6'7, 8'9, 6'7, and 8'5 bus. respectively; while Plot 6, which received single ammonium salts and minerals, only beat the " unmanured " plot by the skin of its teeth 4'1 against 4'9. Out of eleven plots, therefore, it appears that four plots (Nos. 10, 11, 12, and 14) had a much larger decrease in yield than the "unman- ured" plot; while four others (Nos. 5, 6, 7, and 13) were almost as bad as the plot that had received no manure at all. Taking the highest yield that produced by the application of farm- yard manure and the treble ammonium salts and minerals the yields of 39'2 bus. and 38*5 bus. are by no means remarkable. They are both under 5 qr. to the acre, so that at 2 per quarter the return is only about 10 per acre for the grain. To this must be added the sale of the straw, averaging from 34 to 40 cwt. per acre, making the gross return about 12 to 14 per acre. From this must be deducted the cost of labour and manures, rent, rates, and taxes, so that farming and manuring on the Rothamsted principle would appear to be a very precarious business. The cultivation seems to be of the poorest description; in fact it can hardly be described as cultiva- tion at all. "The usual practice ", says Mr. A. D. Hall in his account of the experiments, " is to scuffle the land immediately after harvest, and remove the weeds; the land is then ploughed 5 or 6 in. deep; the mineral and other autumn-sown manures are sown and harrowed in, after which the seed is drilled." One can imagine the condition of the soil 6 in. from the surface after fifty years of such " cultivation ". It must be almost as hard as rock, and impervious to rain, air, or roots. To obtain some idea as to what Wheat really could do if cultivated on horticultural instead of agricultural lines, the writer carried out the fol- lowing experiment at Ealing in 1910: Ordinary English Red and White Wheat obtained from a flour mill 200 seeds of each were sown at a foot apart each way on March 14. They germinated on April 9, and caused some amusement owing to their scanty herbage and lonely appearance. By The Science of the Soil August the plants had tillered and grown fairly well, but were not con- sidered satisfactory, although they averaged 2J to 3| ft. in height. On September 24, the plants being sufficiently ripe were cut, and the following results were tabulated: Out of the 400 plants, about 40 failed altogether, that is 10 per cent. The best plant had 83 stems, and bore 45 ears of corn, the gross weight of the plant being 2 Ib. Other plants had 50 stems and 37 ears; 39 stems and 36 ears; 37 stems and 17 ears; and the very poorest had 24 stems and 11 ears, and a weight of 1 Ib. The average per plant for the whole crop was 46'6 stems, 29*2 ears, and 1'45 Ib. Taking an acre of wheat grown on these lines, there w r ould be about 40,000 plants, producing an aggregate of about 2,000,000 stems and 1,200,000 ears of corn, having a gross weight of nearly 26 tons, of which 19 tons may be regarded as straw, and 7 tons as corn; or over 31 qr. of wheat per acre. By tilling the ground deeply and well on true horticultural principles, there is no doubt but that far larger supplies of wheat two, three, and four times as much could be obtained from the acreage already under that crop. The cost of producing it would be increased naturally, but taking an average of four years' cultivation and manuring, it need not exceed an average of 9 10s. per acre per annum, apart from cutting. The cost of cultivating wheat on horticultural lines, as indicated above, and the receipts, may be estimated as follows: EXPENSES PKK ACRE RECEIPTS PER ACRE s. d. $. d. 1st year, Trenching 3 ft. deep ... 12 / 160 bus. Grain = 20 qr. at 2 = 1 12 tons Straw at 2 = 40 24 2nd ,, Digging 1 ft. deep 2 ( 176 bus. Grain = 22 qr. at 2 = 1 13 tons Straw at 2 = 44 26 3rd ,, ,, ,, ,, 2 / 192 bus. Grain = 24 qr. at 2 = 1 14 tons Straw at 2 = 48 28 4th ,, Double Digging 2 ft. ... 5 /240 bus. Grain = 30 qr. at 2 = 1 16 tons Straw at 2 = 60 32 Hoeing twice each year at 25.s. 5 12 tons Manure each year at 5s. per ton = 3 12 ft 38 Balance 4th year . . . 264 302 302 To the average agricultural mind these figures may appear extraordi- nary. If, however, it is possible to obtain 5 qr. of wheat year after year merely by scuffling over the ground to a depth of 6 in., there is nothing very remarkable in obtaining four and five times as great returns from soil that has been deeply tilled, well manured, and thinly sown. After all an average turn over of 75 10s. per acre is much better than 12 or 14, although the cost of cultivation is greater on horticultural principles than it is on agricultural ones. Once the land has been broken up, if the spade and the fork and the hoe are substituted for the plough, not only would wheat growing be revolutionized, but thousands of men would be kept on Commercial Gardening the land at better wages, and our wheat crops would be increased enor- mously. Agriculturists would do well to consider the above figures before smiling too broadly at them. The annexed diagram (fig. 88) will show at a glance the great advan- tages to be secured by deep tillage. At A, where the soil is dug out 1 ft. deep, the roots are restricted; at B, showing soil dug 2 ft. deep, a larger mass of roots develop and absorb more food; while at c, dug 3 ft. deep, a still larger mass of roots search the soil for food, and no matter how dry Fig. 88. Diagram showing the Root Development in Soil dug 1 ft. deep (A), 2 ft. deep (B), and 3 ft. deep (C). The shaded portion shows the hard, impervious, and unbroken subsoil the summer may be the tender feeding tips are always in the midst of plenty of food and moisture. 9. WATER IN THE SOIL Water, being essential for all plant growth, must be present in suffi- cient quantity in the soil, and in such a condition that it can be absorbed by the roots. Water may be in such abundance in some soils that its presence would be more harmful than useful to the crop. Thus in a clayey soil that has been only broken up with the spade or the plough from 6 in. to 12 in. deep there may be so much water present that the soil becomes chilled and waterlogged, and plants fail to grow because the soil bacteria remain inactive (see p. 125). The quantity of water in a soil depends upon the rainfall. This varies in different parts of the United Kingdom from 24 or 25 in. in the neighbourhood of London, and along the eastern counties of England and Scotland, to 40 in. in the south-western districts; while in the western Highlands, the Lake District, and parts of Wales the annual rainfall is about 80 in. An inch of rain to the acre represents some- thing over 100 tons of water to the acre; so that in the British Islands the amount of water which falls upon an acre of soil varies from 2400 tons to 8000 tons annually. It penetrates the soil more or less readily according to the nature of the soil itself, and the way in which it has been cultivated, Thus on a clayey, uncultivated soil very little rain will The Science of the Soil 117 pass straight downwards. It will flow away from the surface to the ditches, or remain in pools in the shallow places -just as it does on roadways and pavements. On a sandy soil, the rain will pass down and between the particles readily until it comes to the water-table beneath; and in loamy or peaty soils a good deal of water will be absorbed. Different soils will absorb and retain water in 'different proportions, as shown by the following experiment of Schiibler: TABLE SHOWING ABSORPTION AND EVAPORATION OF WATER IN VARIOUS SOILS Water Absorbed Evaporation in by 100 Parts 4 hr. from 100 Ib. of Soil. of Water at 66 F. per cent. Ib. Sand 25 88 Clay, loamy 40 52 Clay, heavy 61 35 Clay, pure ... 70 31 Rich garden soil ... 96 25 Peat mould 190 21 This is a laboratory experiment, and cannot therefore be regarded as giving the same results as one would find in the open field, and in actual practice. So much depends upon the way the soil has been treated. Where the soil has been deeply dug or trenched far more water will be absorbed than where it has been allowed to become hard and baked on the surface. It therefore pays to cultivate the soil deeply and well if full advantage is to be taken of the rainfall, and if the soil is to store up sufficient moisture for the roots of the crops during hot and rainless summers. The above table teaches the market gardener that a soil which has been well dressed with organic material like stable manure, peat-moss litter, &c., will absorb and retain moisture for a very long period but only in accordance as to whether it has been cultivated to a great or little depth. That is the important point for practical growers to bear in mind. Unless the soil has been well opened up by digging, trenching, or subsoil ploughing, it will lose its moisture very rapidly, and crops will suffer intensely in consequence during a hot dry season. How Moisture is Lost. Soils lose moisture in four ways: (1) by natural evaporation from the surface; (2) by bad and shallow cultivation; (3) by transpiration from the leaves of the crops grown; and (4) by the leaves of weeds allowed to grow. The loss by natural evaporation will depend upon the temperature of the atmosphere and the dryness or otherwise of the season. The higher the temperature and the drier the atmosphere the greater the evaporation from the surface. This is so well known to gardeners who grow pro- duce under glass that special care is taken to counteract the heat and u8 Commercial Gardening dryness by saturating both soil and atmosphere with moisture with the hose or water pot. The only market gardeners who do the same thing in the open air in a systematic manner are the intensive cultivators or maratchers in France and Holland. British fruit-growers and market gardeners, owing to the large areas they crop, find it physically impos- sible to apply sufficient moisture to their crops; hence they suffer great losses in dry seasons. The diagram (fig. 89) will give an idea as to how water either rests on the surface of the soil if hard and caked, or how it sinks down to a depth of 1, 2, 3, or more feet if the soil has been broken up to such a depth. It is obvious from the diagram, in which the soil has become hard and baked, or is of a clayey nature and uncultivated, that most of the rain that falls remains on the surface, and will be soon evaporated. In the diagram, where a similar soil has been cultivated and turned up more or less deeply, more water will sink into the soil, and it may be taken that the powers of absorption will be as stated on p. 120, according A B C Fig. 89. Diagram showing Soil dug 1 ft. (A), -2 ft. (B), and 3 ft. (c) deep at the shaded portions. The unshaded portions show the hard, impervious, and unbroken subsoil to the nature of the soil. The deeper, therefore, a soil is cultivated, the more moisture it will hold for the benefit of the crops. LOSS Of Water through the Leaves. In addition to the water lost by natural evaporation and by shallow cultivation, a vast loss is sustained owing to the moisture that is given off from the leaves of the crops. Stephen Hales (b. 1677, d. 1761) was the first to discover that leaves gave off moisture, and an account will be found in his Vegetable Staticks, or Experiments on the Sap of Vegetables, published in 1727. The quantity of water taken out of the soil by various crops is stated by H. W. Wiley, in his Agricultural Analysis, to be as follows per acre: Equal to Inches Crop. Lb. Tons. of Rain per Acre. Wheat 409,832 = 183 nearly 1-83 Clover 1,096,234 489 4-89 Sunflower 12,585,994 = = 5619 nearly 56-19 Cabbage 5,049,194 2254 22-54 Grape vines ... 730,733 326 3-26 Hops ... 4,445,021 1984 19-84 The accuracy of these figures may be doubted. If an acre of Sun- The Science of the Soil 119 flowers, for instance, required 5619 tons of water (equivalent to 56 in. of rain) to mature, it is obvious that they could not be grown in many parts of eastern Great Britain, where the total annual rainfall only averages 24 or 25 in., or 2400 to 2500 tons per annum. As the Sunflower crop would require only about 150 days at the most to mature, from start to finish, something like 38 tons of water (or '38 in. of rain) would have to fall on an acre of ground each day. Assuming that 10,000 Sunflowers were grown to the acre, this would mean that each plant would absorb and transpire about 8J Ib. of water per day. Professor Bentley, in his Manual of Botany, states that "a common Sunflower, 3^ ft. high and weighing 3 Ib., gives off on an average 20 oz. of water; and a Cabbage plant about 19 oz. of fluid in a single day". It may be remarked that a Sunflower 3| ft. high and weighing 3 Ib. is a poor specimen. Taking an average specimen, 6 ft. high and about 6 Ib. in weight, it bears about 30 leaves, each with a superficial area of about 45 sq. in. The total transpiration leaf surface for one Sunflower is therefore about 1350 sq. in. Assuming that a plant of this size will trans- pire only 24 oz. of water per day for 150 days, each plant will transpire in the season 225 Ib. of water from its leaves, or over 1000 tons for a crop of 10,000 plants to the acre. Assuming also that each plant, when fully grown, contains 4 Ib. of water, that would give 40,000 Ib., or about 18 tons, more moisture taken from the soil. It would therefore appear that an acre of Sunflowers would require about 1020 tons of water (equal to 10 in. of rain) in the course of the year. The figures on p. 120 give an idea as to the approximate quantity of water taken out of the soil during the growing season by various crops. It will thus be seen that such crops as Sunflowers, Jerusalem Arti- chokes, and Cabbage crops require at least 10 in. of rain in 150 days to enable them to flourish, while Beetroot and Lettuces require over 23 in. of rain, and Runner Beans require about 26 in. in the course of about 100 days. If all the rain that falls is not absorbed by the soil, it is evident that the crops must suffer, unless moisture can be kept round the roots in some way. Mr. A. D. Hall, in his book on The Soil, calculates that 300 Ib. of water transpired is equivalent to 1 Ib. of dry matter. It is obvious that the amount of water given off will depend largely upon the season, whether wet or dry, hot or cold, and also upon the way the crops are cultivated, and whether they are planted at proper distances apart, and are in a free-growing healthy condition, free from insect pests and fungoid dis- eases. The nature of the crop itself must also be taken into account. Some plants containing very little dry material (e.g. Lettuces, Turnips) would give off more moisture than others of a more woody nature. 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