278 THE STONE FRUITS 



tendency to overbear. Sometimes varieties of these plums 

 will set three or four times as many fruits as the tree can 

 mature, and they will often do this year after year. This 

 overbearing tends to weaken the trees and manv are killed 

 by it. 



The fruit should be thinned immediately after the June 

 drop. Thinning is usually done by hand, and although it 

 seems a rather expensive task it will repay the grower. 

 Good judgment must be used in thinning and the number of 

 fruits allowed to remain will usually vary with every grower. 

 The distance between the plums will depend upon several 

 factors, but a conservative distance is from 3 to 5 inches 

 between each fruit on the limb. 



Pruning. — The plum trees vary widely in their habit of 

 growth and their fruit bearing. Owing to this great varia- 

 tion no well-defined system of pruning will suit all types. 

 Many plums resemble the apricot in their fruit-bearing 

 habits, but still many more are like the cherry and still 

 others show more of an inclination to bear only branch buds 

 on the new wood. 



The plum is subject to sun scald on its trunk and therefore 

 should be headed low. The young trees of all types will 

 need some cutting back and thinning out to develop a good tree . 



Some trees will require pruning to spread them. As the 

 trees become older and more mature very little if any priming 

 will be necessary. Occasionally some thinning out of water 

 sprouts or the removal of a branch which is rubbing will be 

 necessary, but usually no severe pruning will be needed. 



Harvesting. — The plums are perhaps less liable to injury 

 from handling than either the peach or the cherry. As a rule 

 the skin of the plum is tough enough to withstand considerable 

 handling without serious injury. The plum, however, should 

 not be bruised or the skin broken, because this will cause the 

 fruit to decay. 



Some varieties of plums color up long before they are ripe, 

 and it requires a little experience to determine the exact time 

 for harvesting. The plum, however, should not be picked 

 until it is almost ripe, although it should not remain on the 

 tree so long that it will be injured in handling or shipping. 



