226 TREES AS GOOD CITIZENS 



Through city control it becomes a simple matter to 

 see that trees are planted and cared for properly. The 

 Shade Tree Commission, city tree expert or other respon- 

 sible head of the work is in position to settle questions as 

 they arise, including the choice of variety, exact location, 

 details of planting, necessary care and protection and the 

 other points involved in securing best results in shade tree 

 development. Under such central control, uniformity of 

 species along any street is assured by the provision that no 

 property owner may plant an undesirable variety, or one 

 lacking in harmony with its shade tree neighbors. Uni- 

 formity in spacing is brought about by the location being 

 officially approved in its relation to the location of existing 

 or proposed trees. In short, no tree may be planted with- 

 out formal approval of type and placement, and since 

 these two points are the very foundation of good planting 

 the importance of control is obvious. 



Central control may give further uniformity by regu- 

 lating the type of guards that shall be used. This is a 

 minor point, perhaps, but it is not to be ignored in the 

 general effect of street development. 



In protecting trees against insects and diseases, central 

 control is most important. In order that pests may be 

 successfully combated, it is essential that their attacks 

 should be anticipated as frequently as possible, or at least 

 that they should be detected promptly after beginning 

 their destructive work. To the untrained eye this is not 

 always possible. The tree borer, for instance, works in the 

 dark, hiding himself soon after birth by eating his way 

 into the inner wood of the tree, there boring an intricate 

 system of tunnels. To the observer of surface appearances, 

 no damage is visible, possibly for years, or until the injury 

 becomes manifest through dying branches. The tree is 

 then frequently past saving. Under a well-organized 



