SHADE TREES. 



ii 



ous scales, and is often killed by borers, while its branches are liable to be 

 broken by the wind. There are twenty-five thousand trees of this species 

 in Washington, many of which bear injuries received during wind storms. 

 Many also have been headed back on account of their extensive growth and 

 are now diseased and unsightly. The silver maple endures city life very 

 well and, if it escapes its various enemies, develops into a fine though not 

 a durable tree ; and its cultivation is always attended with risk. 



HORSE-CHESTNUT. 



In the Spring, the horse-chestnut is an object of great beauty, but in late 

 summer or autumn, when the red spider and mildew have completed their 

 ravages, it seems unfit for 

 the streets of any city. 

 It is exceedingly tena- 

 cious of life ; few other 

 trees have suffered so 

 much and survived the 

 shock. In the deep good 

 soil of Bonn, the horse- 

 chestnut is a large and 

 splendid tree. In Paris, 

 it is abundantly and suc- 

 cessfully used for plant- 

 ing places and borders. 

 But on the streets of most 

 cities it loses its foliage 

 too early because of 

 drought and the effects of 

 its numerous enemies, so 



aw I nil 



FIG. 1 6. A canopy of horse-chestnuts. Jardin 

 des Tuileries, Paris. 



that it cannot be recom- 

 mended for general street planting. 



HONEY LOCUST. 



The honey locust is a fine tree with many good points, but too thorny for 

 city use and often killed by locust borers. The side branches also have a 

 troublesome way of going into the windows of houses and the pods are 

 somewhat objectionable. 



SUGAR MAPI.E. 



The sugar maple grows more slowly than the silver maple and its 

 branches are not subject to injury from storms. It is likewise free from 

 most insect pests, is easily transplanted, and capable of enduring our 

 severest winters. Unfortunately, however, this beautiful tree does not 

 thrive in cities. Its requirements as to soil and water are unusually exact- 

 ing and its foliage is very sensitive to dust and smoke, especially during 

 periods of drought. I have examined the sugar maple in many cities, but 

 have not found one in which it was cultivated with uniform success. 



