THE CARE OF STREET-TREES 



129 



which the tree is to be cut back. As he stands in one posi- 

 tion he directs the cutting of all the branches that are parallel 

 to the plane of the card. Then he slowly goes round the 

 tree and indicates where the other branches are to be cut. 



Sometimes when large branches are removed close to the 

 trunk, adventitious or dormant buds near the place where 

 the cut was made are stimulated into a forced growth, 

 and they produce suckers or water 

 sprouts. If these are desirable to 

 fill out the crown they should be 

 retained; but if they occur low on 

 the trunk they should be removed, 

 for they rob the upper branches of 

 food materials. 



When to Prune. Careful atten- 

 tion to the time of pruning shade- 

 trees is not so important as in 

 the case of trimming shrubs for 

 flowers and fruit-trees for fruit. 

 Very heavy pruning and heading 

 back of old trees are best done in very late fall or during 

 the winter, when trees are dormant. The store of reserve 

 material will cause a rapid growth of new shoots the follow- 

 ing spring. 



The shaping of trees can be done best when the foliage 

 is on. It is also easier to discover dead, imperfect, and 

 weak branches. For general pruning, therefore, it may be 

 said that any time after midsummer is a good time to prune. 

 During the spring and the early summer, when the sap is 

 most active, it is apt to flow too freely from the wounds, 

 and prevent the adhesion of any dressing, and the bark can 

 be easily stripped from the trunk by accidental splitting of 



Fig. 25. A Dendroscope. 



