26 SHADE TREES FOR NORTH CAROLINA. 



is strengthened and their size increased. In this way it is possible, with- 

 out ever removing any large branch, not only to secure perfect symmetry 

 of crown but to direct the crown into almost any shape desired. Pole 

 shears or clippers (tree pruners) are most convenient for this purpose (see 

 fig. 8). The length of the stem should be secured early by removing the 

 lowest branches. Large branches which would subsequently require re- 

 moval on account of being too low on the stem should not be permitted to 

 develop. They are more quickly removed when small; and swellings are 

 less likely to result in healing. 



PRUNING TO THICKEN FOLIAGE. 



This is done by clipping the ends of the larger lateral branchlets as well 

 as the leader. This checks the increase of the crown in size, both in 

 height and in diameter, and stimulates the growth of interior branchlets 

 with consequent denser leaf cover. While this is especially advisable with 

 evergreen broad-leaf trees, it is also occasionally necessary with deciduous 



11 



Fig. 6. 

 Pig. 6. — Skeleton saw, pruning saw, with tapering frame, for use in narrow spaces. 

 For hand use. 



species which have made rapid growth, forming lank stems and long in- 

 ternodes. Poplars, tulips, and sycamores, as well as other deciduous 

 trees, are frequently much benefitted by having their foliage thus thick- 

 ened, as well as hollies, evergreen magnolia, evergreen cherry, etc. This 

 is also true of the broad-leaf conifer, ginkgo, which is inclined to form an 

 open crown. Few of the other conifers are open to such treatment. It 

 cannot be done in the pines, or larches, or cedrus, but in firs, hemlocks, 

 spruce and retinosporia, the foliage can be thickened by clipping one-half 

 of the season's growth in early summer immediately after the spring 

 growth has been made. Libocedrus and the native cedars and arbor- 

 vitaes can be clipped but not beyond the green spray. 



PRUNING LARGE CROWNS TO REDUCE THEIR SIZE. 



When this is done and it is desired to preserve the natural shape of the 

 crown, both lateral and ascending branches should be equally shortened. 

 The crown is broadened by heavy topping and narrowed by cutting back 

 lateral brandies. It is to be remembered that the shape of Ihc crown 



