42 TREES AS GOOD CITIZENS 



growth is another point for consideration and in this it 

 is as necessary to know what to avoid as what to seek. 

 The lure of rapid growth has been responsible for the 

 planting of numbers of Silver Maples, Carolina Poplars, 

 Water Oaks and other species undesirable for the region 

 where they were planted. It must be remembered that 

 these trees grow rapidly but that they are short lived. 

 A Carolina Poplar or Silver Maple will have to be replaced 

 at about the time a Red Oak, a Sycamore or a Norway 

 Maple has reached its best development. It must be 

 remembered also that careful cultivation is a factor in 

 tree growth, and that some of the slower growing varieties 

 will show more rapid increase, under proper care, than 

 the desirable ones would if left to shift for themselves. 



Shade-giving qualities are also an important factor, 

 particularly for street trees. Too much shade may be 

 as undesirable as too little, and selection should be 

 based on the character and width of the street. For 

 narrow streets it is best to have trees of slender growth 

 or small size, with light foliage, or those in which develop- 

 ment can be controlled by pruning, in order that the sun- 

 light may not be entirely shut oif from the houses and 

 the grass. On thoroughfares of unusual width, the utmost 

 in dignity and effectiveness may be obtained by using the 

 largest trees and allowing full development of the crown. 



A point to be borne in mind is that beauty is not the 

 sole result desired in successful shade tree development. 

 If it were, it would be hard to resist the temptation to use 

 exclusively trees of the broad spreading type, for the sake 

 of the overhanging arch of foliage which would result 

 from the meeting of the branches from the two sides of the 

 street. Experience has shown that, despite the beauty of 

 an archway shade, the dense foliage of the arch may 

 prevent the free circulation of air, shut off sunlight from 



