TOMATOES UNDER GLASS. 



EXPERIMENTS AT THE CORNELL UNIVERSITY EXPERIMENT STATION. 



HE WINTER forcing of tomatoes 

 is little understood by gardeners, 

 yet it is a promising industry for the 

 vicinity of the larger cities. Win- 

 ter tomatoes find a ready sale at 

 40 to 80 cents a pound. The crop 

 demands a high temperature, an 

 abundance of sunlight, and great 

 care in the growing, but the profits, under good 

 management, are correspondingly high. 



A light and tight house is essential, high enough to 

 allow of training the plants. Our preference is a house 

 having a two-thirds span and the ridge eleven feet from 

 the ground ; twenty feet wide and built upon a sharp 

 slope. It follows the lay of the land, running nearly 

 east and west. A north and south house would be pre- 

 ferable, probably, because of the more even distribution 

 of light. The framework is unusually light ; the glass 

 14x24 inches. Our second choice is a house like the first, 

 except that the ridge is two feet lower. We also grow a 

 late spring crop in a pea and lettuce house. 



The importance of direct and strong sunlight was well 

 illustrated in our lightest house last winter. At one end 

 is a low building which shaded a part of the plants after 

 half-past two or three o'clock. The plants within three 

 or four feet of this building bore no fruits whatever, al- 

 though strong and vigorous. At six and seven feet away 

 some fruits were borne, but it was not until some fifteen 

 or twenty feet from the building that a full crop was ob- 

 tained. During the middle of winter the north bench, in 

 our house, produces no more than half as much fruit, 

 even in an unequal-spanned house, as those in direct sun- 

 light. The plants in partial shade grow as well and as 

 large as those in full sun, and they often blossom well, 

 but the fruit does not set. The proper temperature is 

 60° to 65° at night and ten degrees higher for dull days. 

 On bright days it may be allowed to run higher, although 

 we always wish to ventilate at 75°, but a temperature of 

 90° or even 100° can do no harm. Until fruit begins to 

 set, the atmosphere should be kept moist, especially on 

 bright days, but the setting of the fruit is hindered by a 

 humid atmosphere. 



We grow the plants in rich garden loam with a fourth 

 or fifth of its bulk of well rotted manure, and when the 

 plants begin to bear, liquid manure is applied every week, 

 or a top-dressing of manure is given. This may seem ex- 

 travagant fertilizing ; but in house culture the roots are 

 confined in a small space and they have iittle chance to 

 search for food. We find this heavy manuring essential. 



August 9 gave plants fit for transplanting early in Sep- 

 tember. These were planted in permanent quarters 



October 15, and the first fruits were obtained December 

 28. They continued in bearing until near the end of Feb- 

 ruary, when they were trained for a second crop. Plants 

 started November 10 were transplanted into 4-inch pots 

 December 8, and from these pots into permanent quarters 

 February 25. The first fruits were picked May 6, and 

 May 12 the first market picking was obtained. The 

 second lot grew more slowly than the first one, because 

 of the short and dull days of midwinter. 



I prefer to grow tomatoes over brisk bottom heat. The 

 plants may be grown in shallow beds upon the benches, 

 or in boxes or in pots. I prefer i8-inch-square boxes, 

 although we have had good success in beds. The illus- 

 tration on page 550 will give some idea of the arrange- 

 ment of our tomato house. The return pipes lie close 

 upon the ground and are covered with a low platform or 

 bench, made of 3-inch slats with inch spaces between 

 them. The boxes are placed ten inches or a foot apart, 

 and four plants are set in each of those, which are eighteen 

 inches square. We have grown them in lo-inch-square 

 boxes and also in lo-inch pots, but these dry out so quickly 

 that we do not like them. Our boxes are a foot deep. 

 One or two narrow cracks are left in the bottom. A good ' 

 layer of potsherds or clinkers is placed in the bottom for 

 drainage, and the box is then filled two-thirds full of soil. 

 When the fruit begins to set, the box is nearly filled with 

 rich soil and manure. The object of not filling the box 

 at first is to confine the roots in a smaller space and there- 

 fore to hasten fruitfulness — perhaps an imaginary advan- 

 tage — bnt more particularly to allow of an additional 

 stimulus to be given the plant at fruiting time. 



The plants must be trained. For midwinter, when it 

 is necessary to economize sunlight, I prefer to train plants 

 to a single stem. Strong flax cord, the size of wool twine, 

 is used for support. A single strand runs perpendicularly 

 from each plant to a horizontal wire or rafter extending 

 lengthwise the house under the roof. The plant is secured 

 loosely to this support at intervals of a foot or so by means 

 of some broad and soft cord, as bass or raffia. All side 

 shoots are pinched off as they appear, and the leader is 

 ' ' stopped ' ' or pinched off as soon as it reaches the glass, or 

 sometimes when fruits begin to form. In houses of suffi- 

 cient height, I like to train the plants fully six feet high. 

 In midwinter it may be necessary to cut away some of 

 the older leaves, or to cut them in two near the middle, in 

 order to let in light. As the fruit sets, the leaves near 

 the base of the plant begin to die and should be picked off. 

 As soon as the fruit becomes heavy the largest clusters 

 will need to be held up. A sling of raffia is caught over 

 a joint of the plant and is passed under the middle of the 

 cluster. Upon very strong vines the clusters sometimes 

 "break" or push out a shoot from the end. This shoot 

 should be cut off. Tomatoes upon clusters where this 



