364 THE CONIFERS (GYMNOSPERMS) — FORESTS 
310. Shade Trees. — When one has occasion to plant a tree, 
the question often arises as to what is the best kind of tree 
to plant. While much- depends on where the tree is to be 
planted, and on the care it will receive afterwards, there are 
a few general rules that may be kept in mind. For instance, 
elm trees, poplar trees, and silver maple trees have the bad 
habit of clogging waste and sewer pipes in their search for 
water, of which they demand a large supply. Besides, one 
should consider that silver maple trees are brittle and apt to 
split when they become old, and that their shade is light. 
Elm trees in some localities are subject to the attacks of elm 
beetles and require spraying to preserve them. Poplar 
trees are hard to kill when it becomes necessary to remove 
them, owing to their habit of sending up sprouts from the 
roots and from the stump. Horse-chestnut and catalpa 
trees make a great deal of litter, detracting from their useful¬ 
ness as ornamental trees. Other trees, like the Norway 
maple, have the habit of branching so low that they require 
frequent trimming in cities, to prevent their being in the 
way of umbrellas. The trimming is likely to mar their 
symmetry. Hard maple, oak, sycamore, ash, linden, and 
tulip are satisfactory trees for most localities, having all the 
good features and none of the bad ones of the other trees 
mentioned. It should be remembered in planting trees along 
paved streets that the conditions are very hard, and they 
should have special care, otherwise they will die from much 
cutting of the roots and branches, from the attacks of insects, 
and from the lack of food and water. In planting, trees 
should have space enough left between them so that each 
tree may grow on all sides. 
When it becomes necessary to trim a tree, care should be 
taken to saw the limbs off as close to the trunk as possible, 
and to cover the fresh wood with a coat of paint. This 
close cutting will enable the wound to heal readily, and 
the application of paint will exclude bacteria and fungi 
