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 
