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 w r ay. 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 

 Eussian 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. 



FCir. 161.1 



