SWEET POTATO PLANTS 271 



The sweet potato is a strictly tender plant and a heat-lover as 

 well, consequently there is no winter planting, though in drier parts 

 of the state, free from frost, there may be fall plantings which carry 

 their crop well into the winter and for more than half the year 

 fresh potatoes may be taken from the ground, and by proper stor- 

 ing the vegetable may be enjoyed throughout the year. 



Preparation of the Ground. Planting is done at the begin- 

 ning of the frost-free period and the date depends upon the locality. 

 Usually it comes about the first of May, but preparation of the 

 ground should begin earlier to secure good culture and moisture 

 retention as described for other root crops. In regions of good 

 rainfall moisture enough can thus be retained to make the crop or 

 at least start it well. On dry plains it may be necessary to thor- 

 oughly irrigate in the spring before the deep plowing with which 

 the planting is to be made. On loose, lowland soils or in irrigated 

 regions there is often abundant moisture within reach of the plant 

 to serve its purposes and then sweet potatoes may follow a hay or 

 grain crop just as in the practice with common potatoes. Lands 

 which receive enough moisture from below and yet are not wet 

 and cold, produce the crop with least labor and expense, though 

 it is quite feasible to proceed with direct irrigation both for plant- 

 ing and after growth. The sweet potato sends its roots to great 

 distances to find moisture. 



Growing the Plants. The sweet potato grows readily by cut- 

 tings from the growing vine planted out directly in the field if the 

 ground is moist and warm. This method is followed to rapidly 

 multiply a rare variety. The usual method is to plant the crop by 

 using sprouts from potatoes 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. 

 If, however; the hot-bed is used, care must be taken against over- 

 heating. 



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. 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 



