272 CALIFORNIA VEGETABLES 



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 touch- 

 ing 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 

 planted later. 



Some prefer to uncover the potatoes, beginning at one end of 

 the bed, removing the shoots and replacing the covering. 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 secure 

 greater heat in the soil and to facilitate irrigation, but flat culture 

 is also practiced and in some regions is decidedly better. After 

 the land is well prepared and harrowed down smooth, mark off 

 the rows three feet apart and set the plants eighteen inches apart in 

 the row. When the ground is thoroughly warmed by the advance 

 of the season, say in April or May, take the shoots as described 

 above. They must, of course, be kept from drying out, the young 

 roots being very tender. In taking them to the field they must, 

 therefore, be kept in a bucket with water, or in a wet sack, the 

 former being the best. Plant out the shoots eighteen inches apart 

 in the rows, one in a place, settling them down in the soil, deep 

 enough to find permanent moisture. 



Sometimes when the object is to get unusually large potatoes, 

 instead of pulling off and setting out the slips, the potato is lifted 

 out and with every slip a small piece of the potato is cut out and 

 planted with the slip. This method will bring the earliest potatoes, 

 but the number of sets are many less than though the potato be 

 allowed to remain in bed for their continued production. 



Recently a machine has come into use which digs a trench on 

 the top of the ridge and drops water at whatever intervals are de- 



