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 w T ill 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. 

 Honey locust. 

 White elm. 

 Austrian pine. 

 Scotch pine. 

 Black locust. 

 Hackberry. 

 Black walnut. 

 Hardy catalpa. 



[CM-. 161.1 



Trees of which some individuals can not bear 

 seed. 



Osage orange. 

 Russian mulberry. 

 Green ash. 

 Red cedar. 

 Cottonwoods. 

 Willows. 

 Boxelder. 

 Silver maple. 

 Ailanthus. 

 Wild China. 



