LESSONS WITH TREES 157 



years there were none. The exposure to light often greatly aflfects 

 the formation of shoots. Many buds may be broken off by storms, 

 by sleet, by birds, or other natural causes. Perhaps some of the buds 

 formed blossoms instead of shoots. The location of leaves on the last 

 year's growth may be seen by the leaf scars under each of the buds. 

 The new shoots next year will be the only ones which bear leaves. 

 This causes the leaves of the tree to be near the outer surface. 



The exercise is of value in the future study of pruning. 

 Lessons of this kind may be studied 'neath the shade of a tree 

 while resting from garden work (Fig. 89). Light has a 



Fia. 89. — The spreading cherry tree furnishes welcome shade after the garden 



work is over. 



strong effect in controlling the growth of twigs and forming 

 the head pf trees. Fruit trees often tend to grow too tall in 

 the struggle between branches to reach the most light. Cut- 

 ting back is thus made necessary. Abundant branching often 

 causes the parts to rub, and wounds are formed. Thinning 

 a brushy head is good practice. Abundant removal of twigs 

 frequently h'as the effect of forcing growth in other parts. 

 Thus the shape of orchard trees is readily within the control 

 of the pruner. 



