Propagation 79 



claiming they can better place it where desired. Small 

 growers who have seed-beds in the garden sometimes 

 prefer to use lukewarm water containing soap-suds on 

 their plants. The wash-water from the house is com- 

 monly saved for this purpose. The merit of this prac- 

 tice seems to be questionable. At all events, it is im- 

 practicable and undesirable for the planter with more 

 extensive beds. Ordinarily the beds may be allowed 

 to take all rains. 



Hardening-off. — It is recommended that the sprouts 

 be allowed to reach a height of 4 to 5 inches above the 

 surface of the sand before they are removed. A " hard- 

 ening-off " process lasting a week or more, during which 

 the ventilation is increased and the water supply shut 

 off, should be employed before transplanting. This 

 process must be brought on gradually as the time for 

 drawing approaches. Toward the end of the period in 

 which the plants are to remain in the bed, the ventila- 

 tion should be increased by leaving off the cover entirely 

 during the warm part of the day and even in the early 

 morning and late evening considerable more ventilation 

 can be given. When removed entirely, which is advis- 

 able during the last few days before the plants are 

 pulled, the cover should be kept close at hand where it 

 can be put on quickly in case of a late cold spell. 

 Sweet potatoes are very sensitive to frost and even 

 though they have been accustomed to the air, the slight- 

 est frosting will cause serious injury. 



Treatment ^ of seed-bed for disease. — Disease may 

 often appear in the plant-bed after the tubers have been 

 bedded, especially if they have not received the cor- 

 rosive sublimate treatment already discussed. W. F. 

 Massey recommends spraying the bed with bordeaux 



