REJUVENATING THE PLANT 139 



3. Heavy pruning of the top tends to rejuve- 

 nate weak or declining plants. 



This is because the remaining parts receive more 

 food. The proposition is really a corollary of 

 Section 1, but it has such distinct and important 

 applications that it is well to give it an indepen- 

 dent statement. When plants begin to fail from 

 general debility (not from the attacks of insects or 

 fungi), manure or prune them heavily, or do both. 

 It is generally best to remove the weakest parts, 

 particularly if the decline has progressed far ; but 

 if it is desired to save the particular branches 

 which are involved, a heavy pruning of the healthy 

 parts may be expected to throw new activity into 

 the weak ones In many cases, however, it is im- 

 possible to rejuvenate weak branches ; but suck- 

 ers or watersprouts may be developed, and these 

 may form a new head. Old and decrepit peach 

 trees are often headed -back severely for the ex- 

 press purpose of securing this new wood. The 

 tops of birches, maples and other ornamental trees 

 sometimes show signs of failing. If there are no 

 borers or other specific troubles, the tree should 

 be heavily pruned, and if the trunk and roots are 

 sound, renewed activity may be expected. 



Under Section 1 (page 136) we found that weak 

 kinds or varieties of plants should be pruned 

 severely and strong kinds moderately. These re- 

 marks were meant to apply to plants of different 

 habits, not to weakness due to disease or debility; 



