116 TREES IN WINTER 



able. It also assists in conserving the moisture of the soil by 

 forming a loose mulch on the surface that lessens evaporation. 

 The turf around the trees would be better broken up every few 

 years and a good supply of vegetable matte:" added before reseeding. 

 Such a practice, however, is not always practicable, but where the 

 trees are located along borders, it may be followed without seri- 

 ously affecting the appearance of the surroundings. 



PRUNING SHADE TREES 



Trees on the lawn will require very little pruning, the work 

 consisting mainly in the removal of dead or diseased branches. 

 Street trees, on the other hand, require careful training to insure 

 a symmetrical development and to prevent their branches from 

 interfering with the traffic. A well-developed street tree should 

 have a compact and symmetrical head and the j^ranching should 

 commence at a point eigth or ten feet from the ground. The 

 beauty in a row of street trees is largely dependent upon 

 uniformity in size and shape. The individual trees, there- 

 fore, should be as nearly alike as possible. Some will require 

 encouraging to keep them up to the average in size, while others 

 will need to be cut back to keep them down to the average. It 

 should be remembered in this connection that pinining while the 

 tree is dormant stimulates vegetative growth and that pruning 

 during the growing season tends to counteract an excessive growth. 



The branching should start at the same height on each tree. 

 The lower branches need not be cut off until they begin to inter- 

 fere with traffic, and these should be removed gradually. One 

 or two of the lower branches may be removed at intervals of 

 two or three years until the proper height is reached. The base 

 of the head should not project horizontal^, but should ascend 

 obliquely, producing an arched effect and giving more room in the 

 center of the street. 



How to Cut Off a LifuJ) — AYhen it is necessary to head back 

 branches, the cut should be made just beyond a side branch that 

 points in the desired direction. Such a cut, if a large one, 

 should be made on a slant to prevent the accumulation of moisture 

 on the surface. In ordinary pruning a whole branch is removed, 

 and when this is done the cut is made close to the parent branch. 

 Great care should be exercised in preventing the branch from 

 splitting down during the process. This trouble may be avoided 



