This weeding or cleaning is easily done with shears when the crop is
from 3 to 5 years old. Later, mere cutting back of the undesirable
trees with a knife or hatchet maybe practiced. In well-made artificial
plantations this weeding is rarely needed until about the eighth or
tenth year. But in natural growths the young crop is sometimes so dense
as to inordinately interfere with the development of the individual
trees. The stems then remain so slender that there is danger of their
being bent or broken by storm or snow when the growth is thinned out
later. In such cases timely thinning is indicated to stimulate more
rapid development of the rest of the crop. This can be done most
cheaply by cutting swaths or lanes one yard wide and us far apart
through the crop, leaving strips standing. The outer trees of the
strip, at least, will then shoot ahead and become the main crop. These
weeding or improvement cuttings, which must be made gradually and be
repeated every two or three years, are best performed during the summer
months, or in August and September, when it is easy to judge what
should be taken out.