1 8 BULLETIN 205. 



are needed . Their use in many other cities would greatly improve 

 the general condition of street trees. 



PRUNING AND CARING FOR WOUNDS. 



The natural forms of shade trees should be preserved as far as 

 possible ; but since trees are rarely adapted to the requirements 

 of a city street, more or less pruning usually becomes a necessity. 

 Pruning should, however, be indulged in as little as possible, 

 and no branch should be removed from a tree without a good 

 reason. The cutting of trees into various artificial shapes can- 

 not be justified on any reasonable ground whatsoever. 



If a street tree has been properly trained in the nursery, very 

 little pruning is needed, and this only for the first few years 

 after planting, during which time the original form is preserved 

 by trimming the fast growing limbs, removing the crooked ones, 

 and shortening those that droop as they become larger and 

 heavier. When one must use an untrained tree, steps should be 

 taken at once to elevate the trunk and encourage the growth of 

 a straight central stem with subordinate branches. The lower 

 limbs of a tree should never interfere with the street lights or 

 with passing vehicles. In Paris, the height of the trunk is 

 required to be fifteen feet. The top of a tree should not be 

 allowed to become so dense as to exclude the sun from the soil 

 beneath or from buildings near-by. The foliage is also more 

 uniform and better developed when light and air are admitted 

 to the interior of a tree, and this increase in leaf surface adds 

 materially to its healthful effect. 



It often happens that trees have been neglected until very 

 large. To bring them into shape requires considerable care, but 

 it should be undertaken if they interfere with the proper use of 

 the street. Trees that have been trained and are simply over- 

 grown can be easily brought back within bounds by thinning out 

 or shortening the overgrown branches. Old and failing trees 

 may often be stimulated to new growth by judicious pruning. 

 When branches are injured by accident or broken by wind or 

 snow, pruning becomes a necessity. It is also wise to remove 

 all dead branches as soon as they are discovered. 



The best time for general pruning in New York State is in the 



