80 TREES IN WINTER 



cies. The prevailing objections to such a practice are that it breaks 

 up the uniformity and that the temporary trees are likely to be 

 left too long, in this way injuring the permanent planting. Trees 

 radically different in form and coloring, like the Red Oak and 

 Carolina Poplar, should present a pleasing effect when regularly 

 and alternately spaced. AVhen the temporary trees begin to re- 

 strict the supply of sunlight and the supply of plant food and 

 moisture, they should be promptly cut down. 



The Best Species for City Streets — In the selection of spe- 

 cies it is well to keep in mind the width of the street, the height 

 and proximity of buildings, the character of soil, and the relative 

 susceptibility to injury from the effects of insects, diseases, smoke, 

 impure air, escaping gas, 'high and low temperatures, ice storms, 

 and general neglect. The ornamental value of the various species 

 should also be considered. Some trees are peculiar for their flowers, 

 others for their summer or autumn foliage, and still others for their 

 symmetry. Furthermore, a street tree should furnish the required 

 shade, and species differ greatly in this respect. Again, some trees 

 like the staminate Ailanthus are offensive on account of their odor, 

 and others like the Horse-chestnut and the Locusts are objectionable 

 on account of unclean habits. 



The ^Yhite or American Elm is probably the most commonly 

 planted street tree. It makes a tall, graceful growth and has 

 many commendable points. Unfortunately it is subject while young 

 to the attacks of borers and to the ravages of the leaf-beetle and 

 other insects throughout its whole existence. It is still largely 

 planted, especially in suburban sections where there is a desire to 

 produce a natural effect. 



The tendency at the present time is to use for city street plant- 

 ing the species that present a more formal appearance. The fol- 

 lowing are likely to give good results under varying conditions: 

 Red Oak, Pin Oak, Scarlet Oak, Eed Maple, Xorway Maple, Syca- 

 more Maple, American and European Linden, Sycamore, Ginkgo, 

 Ailanthus, Hackberry, Sweetgum. 



Trees of Rapid Growth — Where early results are necessar}^, such 

 varieties as the Carolina Poplar, Box Elder, Hardy Catalpa, Silver 

 Maple, Linden, and Sycamore may be employed. The following 

 table prepared by the late William F. Fox, superintendent of for- 

 ests for the state of New York, gives the relative growth-rate of 



