22 
shade and undergrowth, so that weeds and grass can easily get a 
foothold. Large trees, however, are usually not much damaged 
where moisture is abundant, and the protection furnished to stock 
in such a case may be worth the loss. The principal injury to old 
trees is from trampling. A heavy soil becomes packed until it is 
nearly impervious to water, while sandy ground is worn away and 
the roots are left exposed. 
PRUNING. 
The necessity for pruning depends upon the purpose of the planta- 
tion. In windbreaks and shelterbelts the trees should be allowed to 
branch freely near the ground in order that the density may be in- 
creased. This will furnish better protection, and will also retard 
the growth of weeds and grass. 
Broadleaf species that are planted for ornamental purposes need 
more or less judicious pruning. Nature prunes heavily, as is shown 
by the multitude of small dead branches in the forest. Man aids in 
the development of a symmetrical tree by removing unnecessary or 
unsightly branches before they die. The removal of numerous laterals 
concentrates the growth more on the leading shoots, and increase their 
length. Slender growth should not be encouraged, however, unless 
in a well-protected situation. : 
The natural habit of the Plains species is low and spreading, and 
nature is generally successful in evolving types suited to her needs. 
In a certain sense pruning accompanies cultivation; care makes prun- 
ing more advantageous. Trees left to fight for life with weeds and 
grass should be allowed to do it in their own way. But all the decidu- 
ous trees mentioned in this report will have a better form with prun- 
ing and care than otherwise. In the case of the Osage orange and 
Russian mulberry in particular, severe trimming is necessary to force 
them into good proportions. In figure 5 is shown an Osage hedge 
that has been long neglected, which will now, by thinning and prun- 
ing, be made to produce posts. The results of the same treatment of 
a mulberry row are given in figure 4. 
A good method for securing straight, vigorous young trees is to cut 
them back to the ground one or two years after planting. The root 
system is so well established at this age that strong, rapidly growing 
sprouts are sent up. By removing all but the thriftiest one a tree 
is soon obtained which is better than the original. This method has 
given excellent results in catalpa plantations, and should be used with 
any young tree that is not developing properly, provided it is a species 
that will sprout. 
There is ordinarily no need of pruning conifers. A thriving pine 
or cedar develops symmetrically and appears better when untouched 
by the knife. The red cedar, however, may be cut down to a very 
good evergreen hedge. 
[Cir. 161.] 
