Page:Growing Black Locust Trees.djvu/28

26 trees when cut in making thinnings to improve the growth of the stand will of course become available for use.

There is a widespread habit of allowing black locust trees to grow beyond their age of maturity, which is often 20 to 30 years. Such trees develop heart decay (fig. 17).

This applies more particularly to trees grown in open stands about the farm, rather than to forest-grown trees.

The trees from the second growth or sprout crop, will grow faster and can be harvested at least 5 years sooner than those of the original seedling crop. They are usually less subject to insect attack than trees of seedling origin. To cut the crop of trees would often prove a good, means of renewing badly infested stands of black locust.

Occasionally a landowner objects to putting black locust on his place because he has heard that it is difficult to get rid of it. A sure and simple way to do this is to cut all the locust trees preferably in the spring and turn cattle, sheep, or goats on the land. They will browse the sprouts and kill out all the locusts.

The number and size of fence posts that may be cut from black locust trees of different sizes are often of interest. Obviously the cut from a tree depends upon its height, diameter, and the straightness and soundness of its trunk. In other words, it depends upon the tree's merchantable length, diameter, and soundness.

For example, a black locust tree of regular shape, measuring 8 inches in diameter (outside the bark at 4½ feet above the ground) and 50 feet in height, as shown in table 1, will on an average cut out seven round or equivalent split posts, each 7 feet in length. Of these, four will be 4-inch posts (top diameter inside the bark), two