50 ELEMENTARY FORESTRY. 
White Willow. It is quick-growing, rather long-lived in most 
situations, makes good summer fuel and renews itself very rap- 
idly from the stump. The Green Ash would probably rank next 
Figure 3. A young White Willow windbreak on dry prairie at Coteau 
Farm. Grown entirely by mulching after being well started. 
as a pioneer tree. The White Elm is also very valuable for 
this purpose, but generally should follow the White Willow. 
The Cottonwood may sometimes, though very seldom, be the 
best to use, but on average prairie land it would be better if 
the White Willow or Green Ash were always planted instead. 
After a good windbreak has been secured it is safe to plant 
out the hardy coniferous evergreens and such trees as the 
Mountain Ash, European White Birch and other similar orna- 
mental trees. Wind protection is beneficial to all trees and 
necessary for many of our best ornamental kinds and often 
makes the difference between success and failure in growing 
them. 
Distance Apart. In the planting of groves we should aim 
to get the Jand shaded by the trees as soon as practicable, and to 
keep it covered with a canopy of leaves. The United States 
government recommended the planting of trees four feet apart 
each way, with the idea that when so planted they would quickly 
shade the ground and consequently keep out grass and retard 
evaporation. Some successful plantings have been made on 
this plan, but when planted so closely together the branches 
grow into the rows after a few years and cultivation must be 
discontinued. In this section, where we have so much very 
