THE VEGETABLE GARDEN 349 



poor soils the lime and potash work together to produce potatoes of 

 uniform size and shape, but on rich or alluvial soils the tendency is 

 toward the production of over-large and irregular roots. The lime 

 should be applied the previous season, or at least the autumn before 

 planting the land to sweet potatoes. 



Propagation of Plants. The more common varieties of the 

 sweet potato have for a great many years been propagated by cuttings, 

 or sets, taken either from the potatoes themselves or from growing 

 vines, and as a result the plants have ceased to flower and produce 

 seed. The greater portion of the commercial crop is grown from sets, 

 or "draws," produced by sprouting medium-sized potatoes in a warm 

 bed of soil. 



Where only a small area of sweet potatoes is to be grown for 

 home use, the necessary plants can generally be secured from some 

 one who makes a business of growing them. If an acre or more is to 

 be planted it will in most cases be more economical to prepare a bed 

 and grow the plants. The method of starting the plants will depend 

 upon the locality and the acreage to be planted, the essentials being a 

 bed of warm earth and a covering to protect the young plants during 

 the early springtime. 



Selection of Seed. The potatoes that are to serve as seed from 

 which to grow the plants for the next season's crop should always be 

 selected at the time of digging and housing the crop. For seed pur- 

 poses it is the custom to select the medium or under-sized potatoes, 

 such as are too small for marketing. Those potatoes that will pass 

 through a 2-inch ring or can be circled by the thumb and first finger 

 of a man having a hand of average size are used for seed purposes. 



The seed potatoes should be uniform in size and of the shape 

 desired in the following year's crop. The seed should be free from 

 cuts, bruises, decay, or disease of any kind. Throughout the hand- 

 ling of the seed potatoes they should, not receive any treatment that 

 would break eggs. The seed should always be handled and kept 

 separate from the regular crop. The oftener the seed is handled the 

 greater the danger of decay, and it should not be sorted over until 

 everything is ready for bedding. The best seed is grown from cut- 

 tings taken from the regular plants after they have begun to form 

 vines. These cuttings produce large numbers of medium or small- 

 sized potatoes that are free from diseases and adapted for use as seed 

 the following year. 



Hotbeds. Toward the northern part of the area over which 

 sweet potatoes are grown it is necessary to start the plants in a hotbed 

 in order that the length of season may be sufficient to mature the 

 crop. The roots that are too small for marketing are used for seed, 

 and these are bedded close together in the hotbed and covered with 

 about 2 inches of sand or fine soil, such as leaf mold. The seed should 

 be bedded about five or six weeks before it will be safe to set the 

 plants in the open ground, which is usually about May 15 or May 20. 

 Toward the last the hotbed should be ventilated very freely in order 

 to harden off the plants. 



Drawing the Sets. As a general rule sweet potato plants are set 



