Page:Popular Science Monthly Volume 81.djvu/539

Rh forest that is crowded when young, a natural thinning occurs as it develops. The weaker trees die out. An average acre of mixed woods in the Black Forest of Germany, which at the age of twenty years contained 3,960 trees, contained at the age of forty years 1,013 trees and at the age of eighty years, 346 trees.

A person intending to start a forest should plant the trees in the spring as soon as the frost is out of the ground. The most economical plan probably will be to buy them of a reliable nurseryman. The forestry departments of some states now furnish seedlings at cost. In 1910 the Superintendent of Forests of the state of New York supplied to private parties at cost 2,733,200 trees, being mostly white pine seedlings two years old. The pine produces a crop of cones every two or three years, and if conditions are very favorable, one might gather the cones, which should be done about the first part of September. By drying them in the sun, the seeds can be shaken out. The seeds should be kept in a cool safe place, and can be sown in the spring in a garden bed in the same way that garden seeds are sown, and the first summer must be protected from the sun by lath screens about two feet above the beds, or by an arbor of boughs ten feet high. In muggy weather, the delicate pine plant is liable to a blight called "damping off" and as a preventative should obtain good air currents. When ready for planting they should be carefully taken up with a spade, not pulled up. The roots must not be exposed to the sun at all. The plants must be carried