CULTIVATION OF MEDICINAL PLANTS. 



735 



cuttings should also be protected from strong light, as this tends 

 to increase transpiration, and also* guarded against a dry atmos- 

 phere, which may be accomplished by covering them with glass, 

 particularly during the day, when the weather is dry. Cuttings 

 of hard wood plants intended for outdoor culture should be made 

 in the fall. They should be 6 or 8 inches in length, kept covered 

 with sand in a suitable place during the winter, and planted in the 

 spring. 



FIG. 406. Goldenseal (Hydrastis canadensis) farming under an artificially constructed 

 shade. From Wellcome Materia Medica Farm near Dartford, England. 



In the case of both ginseng and hydrastis, one-year-old plants 

 are often supplied by growers, and, though this is not always desir- 

 able, yet there are conditions where, for experimental purposes, 

 they may be used. It should be emphasized that it is not merely a 

 matter of getting rhizomes or young plants, but a very careful 

 study should be made of the conditions governing soil and light, 

 and which favor the maximum returns from the crop (Figs. 405- 

 407). Caution should be exercised in the use of manure for in- 

 creasing the yield of the crop as well as the plant constituents. 



