THE PLUMS 147 



commercial plantations. The trees should be set from 

 fifteen to twenty feet apart according to the variety. 

 Two-year-old trees are the best to plant. The young 

 trees should be severely pruned back before setting. 

 Careful culture or heavy mulching should be given the 

 young plantation, together with plenty of plant food, 

 especially that rich in potash. 



Many varieties of plums will not set fruit unless the 

 blossoms are cross-pollinated by another variety. This 

 is a common reason for failure with the crop. It is easily 

 avoided by planting two or preferably more varieties 

 near one another, so that the bees and other insects may 

 carry the pollen from tree to tree. These must be 

 sorts, however, that blossom at the same time. In 

 general it is worth while to grow at least a few 

 trees of several sorts in order to be sure of abundant 

 cross-pollination. 



The Domestica Plums are subject to many attacks by 

 insects and fungous diseases. Unless constant watch is 

 kept for Black Knot, San Jose Scale, Fruit Rot, and 

 Curculios the trees are likely soon to become worthless. 

 But these enemies can be controlled and their existence 

 makes the plums even more valuable to the intelligent 

 fruit grower. 



Japanese Plums 



In 1870 a fruit grower in California imported some 

 plum trees from Japan. A few years later the trees 

 began bearing good crops of attractive fruit, so different 

 from the other plums in cultivation that it seemed worth 

 while to propagate the variety. So about 1883 a firm 

 of California nurserymen began selling the trees, naming 



