23 
Pruning may be done with success at any time, “ whenever your 
knife is sharp,” as is sometimes said; but the best time seems to be 
late winter or early spring, just before growth starts. Wounds made 
then begin to heal quickly and have the whole growing season in 
which to recuperate. 
More important than the time of pruning is the kind of cut made. 
Branches should be severed close to the parent stem and in such a 
manner that the exposed surface conforms to its shape. The cut 
should always be clean and smooth. When the ends of twigs are 
removed, a slanting cut is best. Ragged wounds are almost as bad for 
trees as for human beings. In both cases they delay the healing proc- 
ess and are likely to have serious effects. A projecting stub left by 
ignorant or careless pruning dies before it can be covered by new tis- 
sue, and gives disease and insects easy access to the heart of the tree. 
Clean wounds made in pruning forest trees (except some conifers) 
heal quickly, and no treatment is necessary for them unless they are 
very large. A dressing aids healing only by keeping out water and 
fungous enemies; therefore it should be durable and antiseptic. Coal 
tar is a cheap and effective material for dressing the wounds of 
forest trees. Lead paint is recommended for all species. 
SEED BEARING. 
Persons who desire to plant trees often ask, “ Do all trees of this 
species bear seed, or only part of them?” It is a matter of common 
knowledge that the flowers of many kinds of trees are not perfect, but 
consist of staminate and pistillate forms, the latter of which only 
produce seed, and that only when fertilized by pollen from the 
former. Sometimes the same tree produces both kinds of flowers, but 
in many cases only pistillate or only staminate flowers. When the 
latter is true something like half of the trees will be seedless; nor will 
even those which bear pistillate flowers produce seed unless a tree with 
staminate flowers stands near enough for the pollen to reach them. 
In the following list the trees are placed on the first and second 
columns according as the individuals do or do not possess the power 
to fertilize their own flowers. 
Trees all of which may bear seed. Trees of which some individuals can not bear 
Honey locust. Ree en 
White elm. ag ge. 
: : Russian mulberry. 
Austrian pine. of 
fe sh. 
Scotch pine. ee ee 
Black locust. ToDo 
Cottonwoods. 
Hackberry. : sy 
Willows. 
Black walnut. 
a ee Boxelder. 
ardy catalpa. Silver maple. 
Ailanthus. 
Wild China. 
[ Cir. 161.] 
