290 STONE FRUITS 



The time of planting is regulated by the location and in a 

 general way agrees with that of the cherry. There seems to 

 be no advantage in spring planting over fall planting if the 

 climatic conditions are favorable for fall planting. If the 

 soil is well-prepared and the trees are well-ripened they 

 may be set in the fall with good success. If the trees are not 

 in a well-ripened and mature condition, spring planting is 

 preferred. In selecting and planting the different varieties 

 they should be mixed with reference to cross-pollination. 

 Many varieties are sterile or partially sterile, and if they are 

 planted in a solid block with no other fertile varieties they 

 will never set fruit. This is a very important phase of the 

 industry, and it should be thoroughly understood before 

 planting the plum. 



Cultivation. The plums grow and thrive better when the 

 trees are cultivated. The same conditions suggested for the 

 apple apply with equal force to the plum. The orchard should 

 be plowed in the spring. The soil should be cultivated at 

 frequent intervals throughout the spring and the summer 

 until the middle of July or the first of August, when culti- 

 vation should stop. The orchard should then be sown with 

 some cover crop. The cover crop will use up the surplus 

 moisture and the plant food which will check the growth of 

 the trees and they will lipen their wood before cold weather 

 arrives and will pass the winter in good shape. 



The cover crops which are selected depend upon the soil, 

 the locality and the condition of the trees. If the soil is 

 sandy and the orchard located in the southern part of the 

 country, crimson clover, cow peas or soy beans are perhaps 

 the best. If the soil is of the heavier types and the orchard 

 located in the north, rye, buckwheat, peas or mammoth clover 

 is preferred. On sandy soils in the north hairy vetch is 

 excellent. The seed of all cover crops should be sown thickly 

 so that a good stand will be obtained. A common mistake is 

 to have the cover crop too thin and little good is derived from 

 its use. 



Thinning. Thinning is important with many fruits, but 

 perhaps more so with the plum than with any other. Many 

 of the American and the Japanese plums have a great 



