PRUNING. 105 



need occasional pruning 1 to remove or shorten awkward 

 branches, at least while the tree is young and growing- rapidly. 



The Proper Time for Pruning is determined by the effect of the 

 operation upon the health of the tree. Dead branches may 

 be safely removed at any season. The removal of live 

 branches during- the growing- season lessens the leaf surface 

 and hence checks growth. Pruning when the tree is dormant 

 results in a more vigorous growth in the remaining- branches. 

 Wounds made by pruning- just as trees are starting- into 

 growth do not heal over as readily as those made earlier in the 

 spring- or during- the period of active growth in June. Wounds 

 made in autumn or early winter generally heal over well, 

 but are more likely to cause bad injuries than if made at the 

 close of the winter. These considerations and practical ex- 

 perience have brought about the following conclusions as to 

 the best time for pruning : 



Large branches are most safely removed during the latter 

 part of winter before growth starts. Small branches may be 

 safely removed at this time or during the growing season, 

 preferably about the middle of June, but such very hardy 

 trees as the Elm, Ash, Box Elder, White Willow and Cotton - 

 wood may be safely pruned at any time in autumn, winter or 

 spring, while the Mountain Ash, Apple, Plum and Wild 

 Cherry are liable to injury if pruned at any but the most 

 favorable seasons. 



Among the -directions to be followed in good pruning are 

 the following: 



(1) Do not cut off a single branch unless you have a 

 good idea of what you wish to accomplish and the probable 

 effect of so doing on the tree: better not prune at all than 

 to do it without considering the consequences. 



(2) Avoid doing very much pruning at one time, especial- 

 ly on small street trees, which, if they have all their branches 

 removed from the trunks to their final height, are likely to 

 make too much growth at the top for the trunk to support well 

 in high winds. A better way is to remove a part of the lower 

 branches and shorten back in summer those that are to be re- 

 moved later; by such treatment a large part of the strength 

 of the tree goes into the top without increasing the size of the 



