SWEET POTATOES. 325 



on which growth is quickly started with bottom heat. Any 

 of the hot-bed appliances described in the chapter on 

 propagation may be used for this purpose on a small scale, 

 but in the warmer parts of the State it can be done on a 

 large scale for field planting without expense of glass or 

 cloth covering. There is, however, often advantage in an 

 early start with sweet potatoes, and for this the plants 

 must be started when air and soil are too cold. Hot water 

 circulation is being used for bottom heat. If artificial heat 

 is used, care must be taken against overheating. 



To grow plants in the open air, dig a trench four or five 

 feet wide and about two feet deep ; the length according to 

 the number of plants desired. The trench should be dug 

 in light, well-drained soil, in a place protected from cold 

 winds, such as the south side of a building. Put in fresh 

 horse manure and tramp down until about a foot and a 

 half of thickness is secured. Wet it well, 'but not enough 

 to drain, and immediately cover with three or four inches 

 of moist soil. Upon this place the sweet potatoes just as 

 close as they can be put down without touching each other. 

 When done, sift in fine sand between the potatoes and 

 finally cover with three inches of very sandy loam, or even 

 with sand. Keep this bed moist but not wet. Moisture 

 and heat may be retained by covering the bed with two 

 inches of loose straw to be removed as the shoots appear. 

 The plants are ready for use in about eight weeks from 

 the bedding of the tubers, when they show a few green 

 leaves; they can be detached by pulling and will bring 

 their outfit of small roots with them as they are pulled 

 out of the sand. The tubers will then send up other shoots 

 which can be used for later plantings. 



Some prefer to uncover the potatoes, beginning at one 

 end of the bed, removing the shoots and replacing the cov- 

 ering. This lessens the danger of breaking the shoots. 

 Others split the potatoes lengthwise and plant with the 

 cut side down so that all the shoots come from the upper 

 surface, and are thus less liable to break in pulling. 



Planting. Most sweet potatoes are grown on ridges to 



