SHADE TREES. 9 



is unrivalled for vigor and general thriftiness. When these trees show 

 signs of failing, they will be cut down and the avenues replanted. 



The qualities which make the ailanthus especially desirable as a shade 

 tree are its ability to grow in even the most barren soil and to thrive in 

 the midst of smoke and dust and other adverse surroundings peculiar to city 

 streets. When the question is not what tree would be the most ornamental, 

 but what tree would live and grow in a particular locality, then the ailan- 

 thus should certainly be considered. 



NORWAY MAPLE. 



The Norway maple appears to be the best maple we have for street use, 

 though most of the trees I have seen are still comparatively young. Care 

 must be taken to prevent its heading too low and making too dense a shade, 

 but this can be easily done by timely and skillful pruning. Like the sugar 

 maple, it suffers from dust and smoke, though not to the same extent, 

 while it endures other street conditions much better, as may be seen by 

 comparing the two species in any of our cities. After the first two or three 

 years it makes a strong and rapid growth, and develops into a shapely tree 

 well adapted to street use and free from any serious pests. 



GlNKGO. 



The ginkgo is a new and very promising tree from Japan. There is a 

 fine avenue of them in Washington and they seem to stand the winter as 

 far north as Boston, where several young trees have recently been planted. 

 At Rochester, the extremities of the lower limbs are often winter-killed, 

 and in northern Germany it cannot be successfully cultivated on account 

 of the severe cold and injury to its branches from snow. This tree is in 

 many ways an ideal street-tree, and is without enemies of any kind. One 

 must wait many years for shade, however, and the form of the tree must be 

 adapted to street-use by careful pruning. 



The indications are that the ginkgo will make a valuable addition to our 

 list of shade trees ; but experiment alone will definitely determine its value. 

 A new tree often has many advantages in the way of soil and attention 

 which would work wonders if bestowed to an equal degree on some ordi- 

 nary and less esteemed species ; while it might be difficult to say just what 

 effect the vigorous conditions under which many of our city trees exist 

 would have upon the species newly introduced. It is to be hoped that the 

 ginkgo will not have to suffer all that some other trees have borne. 



ASH. 



The ash is a rapid grower and practically free from insects and diseases. 

 Its foliage does not appear so early as to exclude the sun from the soil in 

 spring-time. The wood is strong and valuable, but the branches are badly 

 deformed by the wind. As its roots lie near the surface, it is adapted to 



