298 THE BOOK OF VEGETABLES 



YAM (Dioscored) is a plant of several varieties, all 

 grown for their tuberous roots, but mostly semi-tropi- 

 cal, so that few of them can be grown in the United 

 States. The Jamaica Yams need for successful culture 

 at least fifty inches of rainfall in a year, and must have 

 a long season. Their "heads," or clusters of short roots, 

 may be sprouted in coldframes, and set out when 

 frosts are past, three in a hill, hills six to eight feet 

 apart each way. After five to six months, or less if the 

 heads have been well sprouted, new heads can be dug 

 from under the old, care being taken to leave as many 

 of the roots as possible undisturbed. Subsequent dig- 

 gings are possible, three or more in all to each vine. 

 In each hill a stake should be set, seven to eight feet 

 tall, for the vines. Heads, if whitewashed, and not 

 bruised or cut, will keep well. Of Jamaica Yams the 

 "yampie" is best, the "negro yam" earliest but coarse. 



Barbadoes Yams are again quite different, being 

 either grown from cuttings of the tubers like white 

 potatoes, or else sprouted in a coldframe like sweet 

 potatoes. Field culture is exactly like that for sweet 

 potatoes. 



For the North the Chinese or Japanese Yam is of 

 possible culture, being hardy. Plant the roots or 

 rhizomes, about nine inches long, in hills six feet apart 

 each way, and furnish each with a stake. Or the roots 

 may be sprouted under glass for an earlier start, about 

 the middle of April. Give good culture and water in a 



