222 NEBRASKA STATE HORTICULTURAL SOCIETY 



Choice of species will vary with physical and climatic conditions. 

 For exacting conditions the American elm and the hackberry are among 

 the best. The elm is smoke proof and drought-resisting, but is a prey 

 to the leaf beetle, which, however, may be combatted by spraying. The 

 hackberry does not produce heavy limbs so low on the trunk as elm, 

 which is an advantage. Both species are reasonably fast growing for 

 good trees. Cottonwoods, including Carolina poplar, and boxelders grow 

 faster, but possess few advantages other than hardiness and rapidity of 

 growth. In Denver it is unlawful to plant them. Where not proscribed 

 cottonwoods and boxelders may be used for temporary trees and inter- 

 spersed by the more desirable species which will form the permanent 

 species. The chief danger lies in not removing the transient species at 

 the proper time. 



Conifers are not suitable as street trees, although they are favorites 

 as lawn trees. 



CARE IN PLANTING 



Fall is not a bad time for tree planting, but spring is better. The 

 work in the spring is best done before growth occurs in the young trees, 

 or soon after the frost is out of the ground. 



Great care must be taken to protect the roots, especially the fine 

 roots, from drying. A dry root means a dead root. Usually not over 

 a third or a half of the roots of the young tree are removed with it; 

 hence from a half to two-thirds or more of the crown should be removed, 

 in order to maintain a balance between root and branch. The holes in 

 which the trees are placed should be plenty large, and the soil rich or 

 enriched. Place the stem from two to three inches deeper in the hole 

 than it stood in its original position. Tamp the ground firmly around 

 the roots with the hand or foot, in order to get the soil in close contact 

 with the fine roots. 



Water the ground thoroughly after the tree is planted, and tie the 

 stem with a burlap strip to a stake firmly driven into the ground. The 

 tree will then have an upright stem. Protect the stem against gnawing 

 by horses by placing around the stem a sheath made of chicken wire. 

 Let the sheath be fastened by light wire which will break readily when 

 the growing stem fills the surrounding sheath. 



PRUNING. 



As the young tree grows, pruning had best be done while the branches 

 are so small that a penknife can remove them close to the stem. On 

 older trees, where this has not been done, and the limbs requiring re- 

 moval are large, an undercut with axe or saw is made a few Inches from 

 the stem. Next, the saw is made to sever the limb at a point still further 

 from the stem than the undercut. The short stub resulting is then re- 

 moved by sawing as closely as possil)le to the stem in a manner to pre- 

 vent splitting or stripping of the bark. And finally the scar is painted 



