The forcing book; a manual of the cultivation of vegetables in glass houses

Preface

One of the most interesting and significant evidences of the abiding expansion of horticultural business is the evolution of the glass house within the present century. It is only within the last one or two generations that the growing of plants in glass houses for the purpose of selling the product of bloom or of fruit has come to be important and widespread. The most recent part of the expansion, at least in this country, is the commercial growing of winter vegetables. It speaks well for the prosperity and refinement of our people when they are willing and able to purchase freely of the delicacies of the winter garden. This is one of those branches of agriculture which demands the nicest skill and the closest fellowship with plants. It is, therefore, one in which comparatively few people are fitted to engage, but it must, from the very force of civilization, be one of those occupations which shall gain impetus with time. If it is a business which demands much care and pains, then its promoters must be students. They will need helps. It is this thought which has produced this book.

The writer must hasten to say — what the attentive reader will soon discover — that he cannot consider himself to be an authority upon the subject. It has happened that he has been associated with considerable

PREFACE.

experimental work in the forcing of vegetables during the past few years, and he has endeavored to see much of the forcing industry of the country. In this time there has been a great accumulation of information and of notes which, since there is no adequate literature upon the subject, he has now set down in these pages. The book has been written for the commercial grower of winter vegetables, but the writer will be glad if it shall lead anyone to make the effort to grow the vegetables for his own table. The very obstacles which one must overcome make the effort all the more worth the while ; and the satisfaction of growing a garden when the snow lies deep against the house is of the keenest and most unselfish kind.

The American writing upon vegetable-forcing is very recent. I have referred to most of it at various places in the text. It only remains to say that the basis of much of this book is the series of publications from the Cornell Experiment Station ; and it is justice that I add a list of these papers. This list will also aid the student in tracing the bibliography of the literature of the forcing of plants. The Cornell bulletins upon the forcing of vegetables in glass houses (some of which are permanently out of print) are these : No. 28, Experiments in the Forcing of Tomatoes, June, 1891 ; No. 30, Some Preliminary Studies of the Influence of the Electric Arc Light upon Greenhouse Plants, August, 1891 ; No. 31, Forcing of English Cucumbers, September, 1891 ; No. 41, On the Comparative Merits of Steam and Hot Water for Greenhouse Heating, August, 1892 ; No. 42, Second Report upon Electro-Horticulture, Sep-

(vi)

PREFACE.

tember, 1892 ; No. 43, Some Troubles of Winter Tomatoes, September, 1892 ; No. 53, CEdema of the Tomato, May, 1893 ; No. 55, Greenhouse Notes (Third Report upon Electro-Horticulture, Winter Cauliflowers, Second Report upon Steam and Hot Water Heating), July, 1893 ; No. 94, Damping-Off, May, 1895 ; No. 95, Winter Muskmelons, June, 1895 ; No. 96, Forcing-House Miscellanies (Remarks upon the Heating of Forcing- Houses, Lettuce, Celery Under Glass, Cress in Winter, Forcing Eggplants, Winter Peas, Bees in Greenhouses, Methods of Controlling Greenhouse Pests by Fumigation, Treatment of Carnation Rust), June, 1895.

Whilst this manual discusses only the forcing of kitchen-garden vegetables, the essential principles which are set forth apply with almost equal directness to the forcing of plants for their bloom. It should be added, also, that it is the purpose of the book to treat only those crops which are raised to maturity in glass houses, so that the starting of plants for setting in the open, and all questions of hotbeds and coldframes, are omitted.

I.. H. BAILEY.

Ithaca, N. Y., January i, 1897^

(vii)

Chapter I. Page

Introductory Suggestions i to 15

General Remarks i

Specific Remarks 4

The Category of Forcing Crops 4

Locations for Vegetable Forcing 8

Cost of Heat and Labor 9

CHAPTER II. Construction of the Forcing-House .... 16 to 48

Types and Forms of Houses 16

Some of the Structural Details 24

The Frame 24

The Sash-bar 29

The Plate 30

The Gutter 33

Walls 33

Ventilators 35

The Glass and Glazing 36

Beds and Benches 40

Heating 40

Steam and Hot Water 40

Piping 43

Flues and Stoves 46

Cost of Forcing-houses 46

(ix)

X CONTENTS.

Chapter III. Page

Management of the Forcing-House . . . 49 to 92

Temperatures for the Various Crops 49

Soils for Forced Vegetables 50

The Question of Fertilizers 52

The Connecticut Experiments with Tomatoes . 53

The Connecticut Experiments with Lettuce . . 61

On the Use of Fresh Stable Manure 62

Watering 65

Watering by Sub-irrigation 68

Construction of Beds and Benches for Sub-irrigation 69

Experiments with Lettuce and Other Plants . 72 Conclusions 77

Ventilating and Shading 78

The Electric Light for Forcing-houses . . . . 80

Pollination , 81

Insects and Diseases 83

Methods of Controlling Greenhouse Pests by Fumigation 86 to 92

CHAPTER IV. Lettuce 93 to 107

Temperature 04

I-ight 94

Beds and Benches 94

Soils 96

Growing in Pots gg

Sowing and Transplanting loi

A Grower's Remarks 102

Enemies and Diseases 104

CONTENTS. XI

Chapter V. Page

Cauliflower io8to 114

Unsuccessful Experiments 108

The Successful Crops 109

Subsequent Experience 114

CHAPTER VI. Radish 115 to 126

Cornell Experience 115

Sowing 115

Soil 116

General Management 117

Washington Experience 121

Houses Adapted to Growing Radishes . . . .121

The Soil 122

Planting the Seed 122

Varieties to Plant 124

Preparing the Crop for Market 124

Approximate Yields per Square Foot . . . .125 Temperature, Moisture, Insects and Diseases . 125 Summary 126

CHAPTER VII. Asparagus and Rhubarb 127 to 134

Asparagus 130

John Gardner's Method 132

Forcing in Hotbeds 132

Rhubarb 134

CHAPTER VIII. Miscellaneous Cool Plants 135 to 152

Pea 135

Experiments at Cornell 135

Xn CONTENTS.

PAGE

Celery 139

Salads, Pot-herbs, and Mints 141

Water-cress 141

Garden Cress . 142

Parsley 142

Spinach 142

Dandelion 143

Mustard 143

Mints 143

Onion 144

Beets, Carrots and Turnips 145

Potato 145

Pepino 146

History and Description of the Pepino . . . 147

CHAPTER IX. Tomato 153 to 183

The House 153

Soil and Fertilizers 154

Raising the Plants, and Bearing Age 155

Beds, Benches and Boxes 157

Training 160

Watering 161

Pollination 162

Second Crop 166

Yields and Prices 169

Marketing 174

Animal Parasites 175

Diseases 177

CHAPTER X. ClClMBER 184 to 203

The English Forcing Type of Cucumber 184

General Requirements 186

CONTENTS. Xlll

Cucumber — page

Training i88

Bearing Age 189

Origin of this Type of Cucumber 192

Pollination — Ill-shaped Fruits 195

Crosses 199

Enemies 200

The White Spine Type of Cucumber 201

CHAPTER XL

MUSKMELON 204 to 224

The House 205

The Soil 207

Sowing and Transplanting ... 210

Training 211

Pollinating 214

Yields and Markets 220

Insects and Diseases 221

CHAPTER XII. Miscellaneous Warm Plants 225 to 244

Bean 225

Eggplant 228

Pepper, or Capsicum 238

CHAPTER XIII. Summaries of the Management of the Various Crops 245 to 259

Index 260

THE FORCING-BOOK.

Chapter I. Introductory Suggestions

GENERAL REMARKS.

The growing of vegetables under glass for the winter market is one of the most special and difficult of all horticultural operations. It is a more uncertain and perplexing business than the growing of cut-flowers, because it is newer, less understood, there are comparatively few varieties of vegetables particularly adapted to winter forcing, and the markets are less extensive and more unstable. To succeed with forced vegetables requires great skill in the management of glass houses, close attention to every detail, and the complete control of all the conditions of plant growth. To these requirements must be added a thorough knowledge of the markets, and the ability to have the crop ready at any given time.

No amount of reading or study can make one a successful grower of plants under glass. He must first of all possess a love for the business, a determination to surmount all difficulties, and especially the ability and desire to give personal attention to all the details day by day. Having these requisites, reading and study will aftord him most efficient aid by way of direction and suggestion. One who reads horticultural literature should bear in mind the fact that its value depends very much upon the reader. Instructions should suggest lines of work, and should explain and enforce the fundamental reasons for the various operations ; but the directions are not to be rigidly and perfunctorily applied to the particular work in hand. The reader must check up the printed instructions with his own experiences.

Persons who succeed in the growing of fruits and vegetables in the field do not necessarily succeed with crops under glass. Success out of doors is often the result of favorable conditions of soil and weather ; but under glass the grower must not only know the conditions which the plants require, but he must actually create those conditions. The skill of the horticulturist lies in his ability to override difficulties. Leonard Coates, a well-known horticulturist of California, has recently put this truth into an aphorism : "Let the conditions be adverse, and his measure of success will prove the man."

The person who desires to grow vegetables under glass for market must, first of all, count up the costs and the risks. Glass houses are expensive, and they demand constant attention to repairs. They are short-lived. The humid atmosphere and the high temperature engender decay. The heating is the largest single item of outlay in maintaining the establishment. Moreover, it is an item upon which it is impossible to economize by means of reducing the temperature, for a reduction of temperature means delayed maturity of the crop and, in the case of warmth-loving plants — like cucumbers, melons and tomatoes — it invites debility and disease. Labor is the second great item of expense in maintaining a forcing establishment. This, however, may be economized if the proprietor is willing to lengthen his own hours ; but economy which proceeds so far that each one of the plants does not receive the very best of care, is ruinous in the end.

The risks in the forcing of vegetables are great. In the first place, there are risks of accidents, as fire, frosts and hail. There are risks of serious insect and fungous invasions. But, above all, there are risks arising from lack of

PACKING AND MARKETING. 3

experience and knowledge. One must discover the knack of ventilating, watering, heating and training adapted to every crop, and this can be learned only by patient work and study. Every failure should stimulate inquiry, and the operator should not rest until he has ascertained its cause.

It is imperative that the person who desires to grow vegetables under glass should begin in a small way. Let him begin with a small house — say 20 by 60 feet — and gradually feel his way, both in the growing of the plants and in the marketing of the product. If he is successful in a small house, he need have no hesitation in extending his area, for it is easier to control the conditions of temperature and moisture in a large establishment than in a small one.

As a rule, in all those industries in which a very superior product is to be obtained, and in which the risks are great, the rewards are good to those who succeed. Good winter vegetables, placed attractively upon the market at timely occasions, are sure of ready sales. Quite as many persons fail to market their products successfully as to grow them well. A forced vegetable is a luxury. It is a special product. Its sale depends, therefore, very much upon its beauty and attractiveness. Every tomato and melon should be neatly wrapped in clean, thin paper, and if each wrapper bear the name and address of the grower, so much the better. Great care must be taken to pack the product so that it shall not wilt, nor be touched by frost, nor bruised or soiled in transit. In short, the product must be dainty.

In general, it may be said that the common open market is rarely profitable for winter-forced vegetables, unless they are grown upon such a large scale that the grower controls the market, rather than the market the grower. The person who desires to make money from these crops should secure special markets for them, either by placing them directly in the families of the consumers, or consigning them to dealers who have a particular or fancy trade in such products. The

2 FORC.

choicer and rarer the product, the greater should be the care in finding a market for it. Common things are not worth great effort in the marketing, but uncommon things are worth nothing less than such effort.

A dealer in hothouse vegetables in New York writes that "most all forced vegetables bring good prices in winter, but they must be packed and shipped in first-class order. A good many people raise fine vegetables in winter, but they do not understand the packing, and the products are spoiled in shipping." The average prices of forced vegetables in the New York market for the winter of 1895-6 are given me by this dealer, as follows :

Dec. Jan. Feb.

Cucumbers (forcing

type) per doz. . i 50 2 00 2 50

Peppers . . . per crate (i bus.) . $2 00 to 3 00 3 50 2 50

Tomatoes per lb. . 15 to 20 25 20 to 30

Beans, in bundles of 40 10 to 20 through the winter.

"Chicory, escarole and romain salads generally bring good prices in winter."*

SPECIFIC REMARKS.

The category of forcing crops. — The vegetables which are forced to edible maturity under glass are conveniently distributed into two groups, — the "cool" plants, and the "warm" plants.

The cool plants are such as thrive best in a night tem-

* These three plants are not properly forced vegetables in the sense of being grown in glasshouses, and are, therefore, not included in this book. They are grown in late fall, and are bleached in cellars or in frames ; or, in the case of chicory, the roots (raised from spring-sown seeds) are dug in the fall and stored in a dark cellar, where the leaves soon start. The chicory may also be grown under benches much like asparagus, if it is kept dark in order to bleach it. Escarole is bleached endive. Romain salad is winter Cos lettuce. Sea-kale is often forced in frames after the manner of asparagus, and it might be managed in the forcing-house if necessary.

LIST OF FORCING CROPS. 5

perature of 55° or below, and a day temperature of 65° to 70°. The plants of this category are :

Asparagus,

Rhubarb,

Pea,

Carrot,

Beet,

Cress, mustard, mints, parsley,

Onion,

Spinach,

Celery,

Pepino.

The warm plants demand a night temperature above 55°, and the day temperature may run above 75° when the weather is clear and bright. They are :

Eggplant,

Pepper,

Bean,

The above categories comprise about all the species of vegetables which are actually forced for market in this country, and even of this short list there are a number for which the market is so limited, or the methods of growing them so little understood, that they really have no place in the staple demands of the market. Vegetables of very minor importance as a forced crop are peas, carrots, beets, cress, celery, eggplant, and pepper. In fact, there are only three staple commercial forced vegetables, and tiiese, in the order of their commercial importance, are lettuce, tomatoes, and cucumbers.

It is possible to grow any vegetable under glass, but it is only those products of a perishable nature which can be expected to yield any degree of profit. Those, also, which require a very long season in which to mature, and which yield a small amount of product — such as beets, carrots, spinach, peas— are of little importance for forcing. The Lima beans require a too long season, and they are chiefly consumed in the dry state ; but the common "string" beans are a good forcing crop. There are special reasons why some other vegetables are not forced with profit. Cauliflower, for example, is a most satisfactory crop to grow under glass, but the best heads of the late fall crop are so easily kept through the winter in cold storage as to almost despoil the market for the forced product. Spinach was once forced in cheap houses and in hotbeds and coldframes, but the southern-grown spinach now reaches the market in perfect condition from the holidays until spring. Radishes are more popular in spring than in midwinter but the demand for them in early spring is met more by hotbed-grown roots than by a house-grown product. The forcing of celery is practically unknown, having been made a success, apparently, only in an experimental way. Eggplants require a long season and much heat and care, and the demand for them is slight in winter. The regular season of the vegetable is long, beginning with those from the Gulf states and ending with the October and even November fruits of the north. The pepino is little known, either to growers or to the market. Winter peppers ■ — used for the making of "stuffed peppers" — are in limited demand, and they are readily shipped in from the south. Winter muskmelons are an exceedingly fancy product, and very difficult to grow with good flavor, so the price must be very high to enable them to yield a profit. Squashes and marrows can be grown in glass houses, but the plants require much room, and the product has small commercial value.

The near future will no doubt see many new departures

DEMAND FOR FORCED VEGETABLES. 7

in the forcing of vegetables. The demand for forced beans is already fairly good, and is undoubtedly destined to increase. The other minor forcing crops which are probably destined to receive greater attention are celery, asparagus, rhubarb, muskmelon ; and there may be others which we do not now conceive of as forcing crops. With the increase of population and the augmentation of the appetite for luxuries in the dietary, the forcing of vegetables is bound to become an industry of great importance. It is yet in its merest infancy. It has practically all arisen, in this country, in twenty years, yet the demand for information respecting it, in the Eastern states, is even now very earnest and widespread. There is a constant tendency for consumers to prefer a forced home-grown product to a transported and exotic one. The forced tomatoes generally sell well in the very presence of the cheaper product shipped in from Florida. The best consumers desire the product at first hand from the plant, and they enjoy the sentiment which is attached to the forcing of a plant into the pink of perfection in the very teeth of blizzards. Whilst the author does not desire to urge anyone into the forcing of vegetables, he is nevertheless convinced that the business is bound to open up great possibilities in the future.

It is generally best to devote an entire house to one kind of crop, for every crop demands a particular treatment to insure the most profitable results. Yet it is often advisable to grow an alternation or rotation of crops, in order to employ the house to best advantage, and to meet the requirements of the markets. Houses which are too cold for winter crops of tomatoes or cucumbers may be devoted to lettuce or other cool crops during the cold months, and to the warm crops in early spring and summer. Two crops of lettuce during the winter may be followed by the White Spine type of cucumber for spring and early summer. Winter tomatoes may often be followed advantageously by cucumbers or preceded by late fall melons. Vegetables are often alternated with flowers or with plant stock. In the famous "carnation belt" of Chester county, Pennsylvania, tomatoes are largely grown as an early spring crop, following the crops of carnation cuttings.

Locations for vegetable forcing. — The items which chiefly enter into the choice of an ideal location for the forcing of vegetables are the transportation facilities and the price of fuel. The operator makes his climate, and mixes his soils to order. Yet a sunny climate is always to be preferred, for it is essential to quick and sure results in midwinter that there be an abundance of direct sunlight. The severity of the climate as respects cold is a very minor factor, for the operator is able, in the construction and protection of his house, to make himself very largely independent of the outside temperature without great additional consumption of fuel. Whilst the gardener manufactures his soil, so to speak, yet in certain crops (as in heading lettuce) it is very important that the soil of the neighborhood should be free of hard clay.

The transportation facilities are all-important. The product must reach the market expeditiously, and there should be direct access to several good markets. The product is not bulky, and the expense of shipping it is not heavy. Distance from market, therefore, is a less important factor than frequent and expeditious means of shipping. If one has a large product to ship, the actual distance from market is of still less moment, for the gardener can secure concessions on transportation rates ; but it is nevertheless important that the market be directly accessible. Many of the large vegetable forcers ship their products two and three hundred miles. All winter products are shipped by express.

The vegetable forcing establishments are widely scattered. The larger part of them are in the environs of the large cities of the east, but many of them are in small cities or villages several hours removed from the markets. They can often be established with profit upon farms which are near one or more good railway stations, and when the

Expense of heating and labor. g

farmer desires employment for the winter months. Many of the smaller cities — even of twenty thousand and less — afford a ready market for a considerable quantity of lettuce, tomatoes and cucumbers, making it necessary to ship only a comparatively small surplus to distant markets. A home and personal market is always to be preferred to a distant or metropolitan one.

Cost of heat and labor. — The two important items of expense in the management of a forcing structure, as already said, are the heating and the labor. It is impossible to give any exact estimates of the necessary outlay for these items, because these expenses are most intimately associated with the exposure, tightness, efficiency of the heating apparatus, and handiness of each particular house. A single glass house, standing alone, is more expensive to heat than the same house in a range or nest of houses. In central New York, where the winters are long and severe, a detached house, 20 x 100 ft. in ground area, will generally require, for a tomato-forcing temperature, from 15 to 20 tons of coal for the year, whether heated by steam or hot water. For a lettuce-forcing temperature, one-third less coal is usually sufficient.

A good workman, who is accjuainted with the business, should be able to do all the work of growing tomatoes, except the firing, in two houses 20 x100 ft. of ground surface. In lettuce-forcing, one man will handle four times as great an area after the plants are transplanted. These estimates assume that the houses are convenient, with facilities for watering with a hose. The larger the establishment, the less proportionate help does it require, if the houses are so arranged that the workmen are not required to walk more than 50 or 60 feet from any given point to reach an opening into another house, and if they are not obliged to pass back and forth out of doors while at their v\'ork. It is, therefore, evident that for economy in both heating and labor, a range of two or more parallel houses is more satisfactory than a single house or than several lO INTRODUCTORY SUGGESTIONS,

detached houses. When, however, each house is large enough to completely employ the labor of one or two men, the advantages of the nesting of the houses is not so great ; and it may even be better, in such cases, to have the houses entirely separate, in order to facilitate the hauling of earth and other supplies into them.

Aside from the labor required to grow the plants, the operator must figure on the cost of the heating. It is imperative that the temperatures be kept fairly uniform during the night. In flict, variations of temperature are usually more hurtful at night than at day. For the best results, every forcing establishment should have a night man ; but such a man can not be afforded for a small house. In this case, the gardener must place his dependence upon the self-regulating devices of the modern heaters ; but even then he will need to give some attention to his house on very severe nights. Very much depends upon the faithfulness and efficiency of the night man. Very often the owner will find the temperature of the houses to be ideal at bed-time and at 6 in the morning, while, if he had been astir at 4 o'clock, he would have found it ten degrees too low. He would, if he knew the circumstances, cease to wonder why his crops were slow in growth and always attacked by mildew.

In order to arrive at actual expenditures for heat and labor, I have asked a few of my friends and correspondents — all wide-awake commercial growers — to give me their judgment upon the quantity of coal required to heat for one year a rose house of modern construction, 20 x 100 feet ground surface, even span, 10 ft. high at the ridge. I also asked, "About how large an establishment does it require, in roses or winter tomatoes, to keep one good workman busy during the forcing season, in watering, ventilating, training, picking the product, etc. (not attending to the firing)?" The answers to these questions are given below. Where the size of the house is not specified, it is understood to be 20 x 100 ft., as stated in the problem.

expenses for heat and labor. ii

Ontario —

1. I have two tomato houses, each 20x200 ft., 13 ft. high at the ridge, heated with steam. I used last year no tons of anthracite coal.

One good man will attend to one house 20 x200 ft., in the spring. In the winter, the man and a boy can thoroughly care for two such houses.

Massachusetts —

2. For roses, using hot water, it takes about 18 tons of coal for the year.

One man will care for two to three houses, if he is active and thorough, and keeps them clean and in first-class order.

New York —

3. I am heating 500 lineal feet of rose house, 20 ft. wide and II ft. high, at a cost (last year) of I333. This is about 65 cents per lineal foot. The system is hot water in small pipes.

For roses, a good man should manage 400 lineal feet of a house 20 ft. wide.

4. I should estimate 12 tons of coal. This is about my actual outlay in the winter of 1895-6.

A man should handle 8,000 or 10,000 sq. ft. of glass, in roses.

5. I have about 15,000 square feet of glass, in ten houses. I grow roses, carnations, violets, plants, etc. Four of my own family, including myself, work in the houses, and I usually keep one man besides. Outside of my own family, it costs me about |2,ooo a year to run my place, — for coal, help, repairs, water rent, taxes, bulbs, insurance, lumber for boxes, and all other incidentals. My houses are in good condition, and I keep the place in first-class order.

6. I judge that a single rose house 20x100 ft., in this climate (Mohawk Valley), kept at rose-forcing temperature, would take about 25 tons of anthracite coal a year.

12 INTRODUCTORV SUGGESTiONS .

In a nest or block of several houses, the heatmg could probably be done with 20 tons.

In rose-forcing, a careful and industrious man can take care of about 10,000 sq. ft. of glass. With a smart boy for weeding and cleaning up, he could handle 5,000 ft. more.

7. To keep an average temperature of 60°, for roses, by steam, would require about 18 tons of hard coal. Much will depend upon the boiler, the placing of the radiating surface, and the carefulness of the fireman.

With things conveniently arranged, one smart man could care for a rose house 20 ft. wide and 250 to 300 ft. long.

8. I grow violets, and heat with water. I use 60 to 70 tons of hard coal for 15,000 sq. ft. of glass.

Michigan —

9. With coal at $2.75 per ton, and including fireman's wages, it will cost anywhere from I75 to $125 per year, depending upon the efficiency of the boiler and the severity of the season.

Much depends upon the handiness of the place, and how neat the proprietor wants to keep his house. For the most thorough care, one man can manage, of roses, 5.000 to 6,000 sq. ft. of glass.

10. Last season, I used 8^4 tons of Hocking Valley lump coal per 1,000 sq. ft. of glass for roses, and 6)4 tons for carnations and violets mixed. I use steam.