INJURIES TO TREES. 111 
may be prevented by breaking up the crust or by thinly scat- 
tering over the snow some sand, ashes or other material that 
will absorb the sun’s heat and cause the crust to melt before the 
snow underneath melts. This injury seldom occurs except 
under drifts, and a little good judgment in selecting the loca- 
tion and arranging the windbreak so as to prevent drifts may 
obviate this source of injury. 
Drouth. [njuries from drouth may be prevented to a great 
extent by constant cultivation, but where this cannot be done 
mulching is a good substitute. Attention to thinning at the 
proper time so as not to get the soil filled with roots will also 
Figure 28. Section of Trunk of 
Sun-scalded Basswood. Showing 
dead bark and amount of wood de- 
cayed. The top and roots of the 
tree from which this section was 
cut were perfectly healthy at the 
time when the trunk broke off at 
the sun-scald. 
Figure 27. Trunk of 
Soft Maple badly sun- 
scalded. 
help to prevent injury from drouth. Willow windbreaks can be 
grown without any cultivation, after being once well established, 
in the driest portion of Minnesota, if they are kept mulched with 
straw or litter for six feet on each side. Mulching also prevents 
injury from severe freezing of the roots. 
