GLASS HOUSES FOR VEGETABLE CROPS 



123 



set about one foot in the soil. Boards sixteen feet 

 long are nailed across the long way and spliced 

 at the posts, forming the joists of the structure. 

 Stringers, 1x3 inches, are then nailed across the 

 boards, the. stringers in turn supporting plastering 

 laths, nailed about one inch apart. The shed may 

 be of any height desired, but for ease in cultiva- 

 tion it should be at least seven feet high. 



Cloth screen. — In recent times, the cheese-cloth 

 screen has come into very general use in tent-mak- 

 ing on a large scale. The screens may be either 

 open or closed at the sides, and the height will vary 

 according to the crop and the cultivation to be 

 given. Details of the cost of such screens per acre 

 are available. When 2x4 scantlings are used for 

 posts and good support is given overhead by means 

 of scantling and stout wire, the materials and labor 

 have been variously estimated at $300 to $350 per 

 acre the first year. The lighter grades of cheese- 

 cloth, which are preferable for most cultures, can- 

 not well be used a second season ; nevertheless, 

 the cost for the second and subsequent years will 

 be materially lessened. Heavier grades of cloth may 

 be used in some cases. Cloth is now manufactured 

 in sixteen and one-half-foot breadths for this pur- 

 pose. " Domestic " is sometimes to be recommended ; 

 for small, more resistant covers, such as for cold- 

 frames, this material may be treated with linseed oil. 



A good shelter -tent for tobacco, and, conse- 

 quently, one suitable for almost any shade - crop, 

 may be constructed as follows : 



Posts of pine, chestnut, locust or other durable 

 wood, eleven feet long are placed two feet in the 

 ground and sixteen and one-half feet apart each 

 way. Sixteen -and -one -half -foot stringers, 2x4 

 inches, nailed at the top of the posts, run one way, 

 and across the other way are stretched No. 9 cable 

 wires, stapled to each post and secured at the bor- 

 ders of the field by stakes placed six to nine feet 

 beyond the tent borders and connected by a base- 

 board. Two lines of smaller wire (No. 12) are placed 

 between and parallel to the heavy cables, hence, 

 five and one-half feet apart. The lighter wire may 

 also be run along the stringers and baseboard, over 

 which wire may be wrapped the selvage of the 

 cloth when stapled. G. B. cloth of a special width 

 (sixteen and one-half feet) may be employed in this 

 construction, or a heavier grade if it is hoped to use 

 the cloth through a second year. G. B. cloth is 

 somewhat heavier than cheese-cloth. At the two 

 open sides twelve -foot cloth may be employed. 

 When the shade is desired for only a part of the 

 growing season this construction may be consid- 

 erably simplified by reducing the height of the 

 shed, the size of timbers, and the like. 



Shelter-tents in the form of propagating-houses 

 could be used advantageously in those sections in 

 which the winters are mild, but where some form 

 of shed is essential. 



Small frames covered with cloth for coldframe 

 purposes should be painted with raw linseed oil if 

 imperviousness and durability are desired. 



Miscellaneous screens. — In some regions, mat- 

 tings may be cheaply prepared from plant products. 

 In the far South palmetto leaves have been used 



successfully, and straws of various kinds have been 

 employed in countries where labor is cheap. In the 

 Riviera section of Prance and Italy a very common 

 species of heath. Erica arborea, is valuable for this 

 purpose. Its uniform height after a few years of 

 growth, the slender yet dense branches, and its 

 lightness, render it very efficient and remarkably 

 cheap. Bamboo has been employed where it is 

 sufficiently common. 



Literature. 



General references: The Pineapple Industry in 

 the United States, Yearbook United States Depart- 

 ment of Agriculture, 1895, p. 274 ; American Gin- 

 seng, Bulletin No. 16 (revised edition). Division of 

 Botany, United States Department of Agriculture, 

 1898 ; Growing Sumatra Tobacco under Shade, 

 Bulletin No. 20, Bureau of Soils, United States 

 Department of Agriculture, 1902 ; Growing Straw- 

 berries Under Cover, The Strawberry Specialist, 

 February, 1902 ; Experiments in Ginseng Culture, 

 Bulletin No. 62, Pennsylvania Agricultural Experi- 

 ment Station, 1903 ; Shading, Proceedings of the 

 Society for Horticultural Science, 1903 (several 

 papers); An Experiment in Shading Strawberries, 

 Bulletin No. 246, New York (Geneva) Agricultural 

 Experiment Station, 1904 ; Tent - Covering for 

 Vegetables, Rhode Island Experiment Station Re- 

 ports, 1904 and 1905 ; Experiments in Growing 

 Sumatra Tobacco Under Shelter-Tent, Bulletin No. 

 72, Pennsylvania Agricultural Experiment Station, 

 1905 ; Tent-Grown Berries and Celery, American 

 Culturist, Vol. 67, p. 2, 1905. 



Physiological references : Physiology of Plants, 

 Vines, Oxford ; Pfeffer's Physiology of Plants, 

 Vols. I, II and III, Ewart, Oxford ; Effect of Light 

 upon Plants, MacDougal, Memoirs of the New York 

 Botanical Garden, 1903. 



GLASSHOUSES FOR VEGETABLE CROPS 



By L. R. Taft 



For many years gardeners made use of cold- 

 frames and hotbeds for the starting of vegetable 

 plants in the spring, and for the forcing of lettuce 

 and radishes, to get them on the market before 

 they could be produced in the open air. A de- 

 mand soon sprang up for a great variety of other 

 vegetables, and it was found that, if they could 

 be produced throughout the winter months, the 

 prices they would bring would be sufficiently 

 remunerative to make their culture very profit- 

 able. This has led to the erection of numerous 

 forms of vegetable forcing-houses, and some of 

 the ranges are so extensive as to cover several 

 acres. Some of the larger houses are several 

 hundred feet in length and fifty to one hundred 

 feet in width, and are so arranged as to permit 

 teams to be driven through to bring in soil and 

 manure; and horses are often used for plowing 

 and working the ground. The modern vegetable 

 forcing-house makes it possible to produce crops 

 of all kinds of vegetables with comparatively 

 little risk, and with far less labor and expense 



