140 



rRINCiri.ES AXD FRAtTICE OF PRUNING 



continues to flow upward there is a chance that the parts 

 of the stem above and below the girdle will unite and 

 form new conduits for elaborated food to reach the parts 

 below the girdle, especially the roots. The season when 

 the injury occurs has much to do with the healing. 



Girdles which occur in 

 spring may be healed by 

 autumn ; those made in late 

 summer, fall and early 

 winter may cavise such loss 

 of moisture that the inner 

 bark, the cambium and the 

 sap-wood may die at the 

 point of girdling and the tree 

 die before spring. This 

 furnishes a hint as to killing 

 trees by girdling: do the 

 work in late summer and 

 make the cut below the sap- 

 wood. 



127. Prevention of crotch 

 splitting. — It is far easier 

 to prevent than to cure the 

 splitting of a Y-crotch. 

 Nursery trees, which have 

 two branches of practically 

 equal size, especially if both 

 are almost vertical, and 

 thus form an acute angle, 

 are sure to lireak later be- 

 cause the leverage will crack 

 the bark and allow decay to 

 enter and weaken the 

 union (Fig. 98). As the leverage increases and the decay 

 descends farther into the trunk the union becomes so 

 weak that one or both the branches will break and thus 

 ruin the tree. Nursery and other young trees with Y- 



FIG. 98— HOW TO HANDLE YOUNG 

 FORKED TREE 

 When limbs occur below' the natural 

 head they should be cut oPF as close to 

 the trunk as possible, unless they are 

 so large that the cut will make a dan- 

 ce rous wound. Then they should be 

 shortened to a few inches to prevent 

 their making much growth and the stubs 

 removed the following season. In this 

 case the branch cut to a stub would 

 have formed a Y-crotch. Had there 

 been no good head above, the cutting 

 back would have allowed a new limb to 

 form. (See text.) 



