CHAPTER VI 



GROWING PLANTS UNDER COVER 



»OUSES IN WHICH PLANTS MAY BE GROWN have come to be one of the necessi- 

 ties of agriculture. Until recently, these houses have been chiefly glass structures 

 used for the so-called horticultural crops; but various slat-covered sheds have been 

 devised to protect crops and plants in the extreme South from sudden periods of cold, 

 and now the cloth-covered house has begun to come into somewhat extensive use, 

 not only for horticultural plants but for plants that are customarily grown as field 

 crops. The demand for certain high-class products the entire year has made it nec- 

 essary to protect plants from heat and sun and storms in summer as well as from 

 cold and snow in the winter, and the cloth house is often substituted in summer for 

 the hot and uncongenial whitewashed glass house. Moreover, it is now found that certain field crops, 

 of which some kinds of tobacco are examples, actually thrive better and produce a better product when 

 protected from the sun. Hereby has also arisen a new subject in agriculture, — the study of the effect 

 of shade on plants. With the ever-increas- 

 ing niceties of agriculture, protection to 

 plants in summer will assume added im- 

 portance. 



All this means that we are constantly 

 pressed by the necessity of growing plants 

 under conditions of control; and this control 

 now runs the round of the year. The gar- 

 deners have long practiced such control, and 

 they have carried the cultivation of plants 

 to its greatest perfection. These ideas are 

 now working out into general field condi- 

 tions, demanding a new kind of crop man- 

 agement. The general subject of plant-grow- 

 ing under cover is scarcely germane to the 

 present work. It is discussed in its many 

 relations in the Cyclopedia of American 

 Horticulture. Two phases of it may be considered to be within the scope of this volume, — the growing 

 of plants under shade (the subject will be referred to again under Tobacco in Part III), and the making 

 of glass houses for the cultivation of vegetable-garden crops. Figs. 172 to 178 illustrate some of the 

 new practices; see, also, page 100, Vol. I. In addition to these phases, it may be worth while to add 

 to the chapter some advice to the farm-wife on the growing of plants in windows. 



Fig. 172. 



A lath-covered nursery house, in which young camellias 

 are grown. 



THE SHADING OF PLANTS 



By B. M. Duggar 



The shading of plants is a relative expression. 

 It is qualitative and means simply reduced light 

 intensity. As used by horticulturists, shading has 

 reference most frequently to half or partial shade, 

 or to the growth of plants under some form of 

 improvised screen. The extremes of shading are 

 great ; and properly to circumscribe the subject 

 we must consider all plants exposed to grades of a 

 light intensity between bright diffused light, as 

 one extreme, and the darkness of cellara and 

 caves, as the other extreme. 



Shading is a distinct phase of horticultural 

 work, and it has its physiological, or fundamental, 

 side. Such quantitative physiological work as has 

 been done relates, for the most part, to absolute 

 shading, or darkness, and an insignificant amount 

 of accurate physiological data have to do with half 

 or partial shade, which latter is more important 

 horticulturally. The physiological work is not yet 

 so helpful as it might be, but some of the general 

 principles modifying form, size and quality of 

 plants in shade or darkness enable us better to 

 direct half-shade operations, and better to interpret 

 the results that may be secured. The subject offers 

 an interesting field of investigation. 



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