TREES AND SHRUBS 109 
well as the trees in a grove. In the latter case they protect 
one another and shade the ground, thus keeping it mellow 
and moist and preventing the growth of grass. To keep 
snowdrifts from forming among the trees and breaking them 
down, a row of willows should be set four or five rods to the 
north. This forms a trap and causes the snow to lodge be- 
tween it and the windbreak proper. 
For this shelter belt any trees may be used that are adapted 
to the climate, especially such as thrive in fairly close plant- 
ings. It is well to use several species in combination — some 
fast-growing and others of a more permanent character. The 
most effective windbreaks are formed by the evergreens. 
Planting and Care. — A large proportion of the trees and 
shrubs set out annually fail to grow, and the commonest 
cause of such failure is that they were already nearly dead 
when planted. It may be that they came from a distant 
nursery and dried out too much on the way, but too often 
they are killed after arrival by exposure of the roots to wind 
and sun. It has been well said that a tree out of the ground 
is like a fish out of water; therefore, the roots must in some 
way be kept moist until they are restored to the ground. 
If allowed to become dry their diminished vitality may not 
be sufficient to start the growth, or, at any rate, not sufficient 
to pull them safely through the first season. 
The ground should be well prepared before planting. If 
possible it should be plowed and cultivated in the same 
manner as for the seed bed of an ordinary field crop. The 
hole should be dug of ample width and depth to receive the 
roots without bending or crowding and to set the plant some- 
what lower than it stood before. When nurseries sell trees 
and shrubs they usually furnish directions for their planting 
and care, and these should be diligently carried out. 
