PRUNING OF PLANTS. 279 



2. The chief disadvantage is the waste of 

 energy of the plant in the loss of the accumu- 

 lated food supply by the removal of the terminal 

 portions of the branches. 



EXERCISE n. To study the effect of fall and spring 

 pruning, let the student remove several small branches 

 of as many different kinds of trees as are accessible, 

 carefully labeling each branch pruned with the student's 

 name and the date of pruning. 



In the spring let them prune off as many more 

 branches from the same trees and label with date. 



Just before school closes for the year critically exam- 

 ine all the branches pruned. Compare and tabulate 

 results. Was the result in each case due to the time of 

 pruning or to the position and nature of the cut ? 



C. WHY TO PRUNE. 



One should never remove a limb or even a 

 twig from a tree without knowing why. 

 I. Pruning at Transplanting. 



The utmost care should be taken in lifting 

 plants for transplanting, but even then many of 

 the fine feeding roots will be broken off or 

 mutilated ; consequently, the equilibrium be- 

 tween root and leaf will have been destroyed. 



To re-establish the equilibrium : first, all the 

 mutilated roots should be cut off, so that the 

 energy of the plant may not be wasted in trying 

 to restore these injured parts ; second, the leaf- 

 bearing surface should be reduced to correspond 

 to the loss of root-system. This principle holds 

 good in the transplanting of any plant. 



