14 BULLETIN 1538, U. S. DEPARTMENT OF AGRICULTURE. 
plantations, even of the hardy black walnut, have been killed back 
to the ground by severe early frosts and winter freezing when culti- 
vation was continued too late in the growing season. ~ 
It is not necessary that the entire cost of cultivation be borne 
y the plantation. Field crops of corn, potatoes, or beans may be 
grown between the rows for the first one or two years. These will 
not only yield a revenue to the owner, but their cultivatiion will 
benefit the young trees. Sometimes all of the cost of cultivating can 
be charged against the field crop, making a considerable difference 
in the final cost of the plantation. 
The number of years in which cultivation is necessary and the 
amount of it each year will depend, of course, upon the rapidity of 
growth of the species planted and the spacing of the trees in the 
plantation. Some planters have found two cultivations a year for- 
three years sufficient, except under unusually trying conditions. 
A three-year period should be ample, with possibly three or four 
cultivations during each of the first two seasons. The work may be 
done at first with a two-horse cultivator, and later, when the trees 
become larger, with a one-horse cultivator. 
THINNING. 
Every forest plantation reaches a condition after a few years 
when some of the standing trees should be cut out. The removal 
of undesirable trees is called a thinning. The principle is the same 
as that applied by truck gardeners to vegetable crops which are 
thinned out in order to get the best development of a portion of the 
crop rather than a meager development of the whole. The struggle 
for existence between the trees of the stand first induces rapid height 
growth and kills the lower branches, but, if allowed to continue, the 
more vigorous trees are prevented from making their best diameter 
growth by the presence of the less vigorous ones. 
Where there is a poor market for the product from thinnings 
the operation will scarcely pay for itself; where the market is good, 
however, thinnings have been made at a net gain of from 10 cents 
to. $2 per cord.t. In the more widely spaced plantations thinnings 
will not be necessary until the product is of merchantable size. The 
future, moreover, promises a better market for small-sized material 
than exists at present, which will make thinnings profitable in stands 
in which now they would not be. In small plantations thinnings 
may be carried on by the owner at odd times at no cost other than his 
own labor. When poles are cut for some farm use a little care in 
their selection looking to the betterment of the stand will insure a 
enude form of thinning. 
1 Bulletin No. 2, State Forester’s Office, M ee ee 
