PRUNING SHADE TREES 
i39 
given attention. If the roots have been broken or other¬ 
wise injured in digging or handling, the injured portions 
should be removed by clean cutting with a sharp knife. 
Healing and the natural growth of the root will progress 
from a surface which has been cleanly cut, while decay 
and death are likely to follow the ragged break or abrasion. 
For the top pruning there should be removal of all 
branches that can be spared. The amount to be pruned 
varies with species. Oaks, for instance, require much 
more cutting than do Norway Maples and Elms, but in 
many cases it may be said that three-fourths of the leaf- 
buds should be removed. This may seem drastic, but it 
is necessary for satisfactory growth. The purpose of the 
seemingly severe pruning is to reduce the amount of leaf 
surface the tree must support the first year. This 
decreases the amount of moisture that must be supplied 
to the top by the roots, and the lessened drain enables 
the root system to use this strength in becoming firmly 
established in the soil. In this pruning it is not always 
necessary to interfere with the shape of the crown, but 
even when it does involve such sacrifice the pruning 
should be done. Form can be regained after the tree has 
become established, but proper growth cannot be achieved 
without the preliminary pruning. New growth, to replace 
the branches which have been cut off will start close to 
the stem, and this serves a useful purpose through estab¬ 
lishing a compact top. Without this pruning the tree 
may not live, and even if it does survive, its crown will 
be ragged and its foliage lacking in density. 
In pruning at planting time, where only the end of a 
branch is to be removed, the cutting should be done 
immediately above a strong bud, and care should be taken 
to see that the bud which remains is one which points 
in the direction toward which growth of the limb is 
