308 THE WINTER PRUNING. 



throws out nothing but sickly foliage, the removal 

 of a part of the top, with judicious manuring, 

 strengthens the remaining parts. Canker and other 

 diseases are often formed by too close pruning when 

 the roots are very strong. Withholding the knife 

 entirely will help to stay it, although a more effect- 

 ual cure is wrought by root-pruning. 



The season of priming. This depends upon the 

 end to be attained. As a general rule these seasons 

 are two, — winter and summer. 



If the winter pruning is done in the autumn, as 

 soon as the growth is ripe there is danger from a 

 warm season following that the tree would push 

 forth a soft growth, on account of the stimulus given 

 by severe cutting. "When done in early winter, the 

 end of the shoot which is cut does not heal, because 

 the energies of the tree are dormant, and it becomes 

 an unsightly black knot, requiring a pruning in the 

 spring to remove it. If the invigoration of the tree 

 is the object, this should be performed in the spring 

 before the buds have started, and after all danger 

 from severe frost is past. If it is desired to check 

 undue luxuriance, it should be done after the buds 

 have well started, or are even in leaf The plum is 

 very stout in its growth, and the more it is cut, the 

 more luxuriant does it become. When it is neces- 

 sary to use the knife, it should be when the buds 

 are swollen, or the tree is coming into leaf. As it 



