SWEET POTATOES 425 



lumber, and the soil, which must be very sandy, should be placed 

 3 or 4 inches deep over the bottom. The potatoes are placed on 

 this and covered to the depth of I J or 2 inches with clean sand 

 which is free from earth or decaying organic matter. The soil 

 should be moistened at the time of placing the tubers in position, 

 and the hotbed should be kept at a temperature of from 80 to 

 85 F. for a number of days. The bed so constructed can be 

 covered with either sash or cloth, duck or muslin being often 

 used. Beds constructed in this fashion can be from 80 to 200 feet 



FIG. 161. Sweet-potato propagating bed 



in length and from 16 to 30 feet in width. Sixteen feet is a con- 

 venient width, wider beds being less satisfactory because of the 

 difficulty of watering and pulling the sets. 1 



In latitudes south of Washington, where the winters are not 

 sufficiently severe to destroy the roots if left in the ground, a prac- 

 tice sometimes followed is to leave a sufficient quantity of sweet 

 potatoes in the field where they grew, to furnish sets for the next 

 season's plantation. Or, where this is not practicable, the seed 

 potatoes may be placed in a temporary seed bed, which should be 



1 See pages 43 and 44 for further description. 



