INJURIES TO TREES. 



Ill 



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. Injuries 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. 



