PLANTING AND CARE OF STREET TREES 221 



The New York Medical Society more than a century ago resolved 

 that one of the most effective means for mitigating intense heat of the 

 summer months and diminishing the death rate among children is the 

 cultivation of an adequate number of trees in the streets. 



THE IDEAL STREET. 



When a street is laid out, and prior to tree planting, a soil survey 

 should be made in order to determine the soil's fertility, whether enrich- 

 ing by fertilizers and deep rich dirt is advisable, and to learn of the 

 presence of and depth to hard pan. 



It may be necessary to break the impervious sub-soil. Longevity of 

 trees as well as the rapidity of growth depend considerably on soil con- 

 ditions. Well-rotted stable manure mixed with soil makes a suitable 

 bed in which to set the young tree, if the street soil is not rich. A 

 top dressing of the following chemicals is also very beneficial to trees 

 already set out: 



Nitrate of soda, 6 pounds. 



Sulphate of potash, 6 pounds. 



Acid phosphate, 8 pounds. 



Mix thoroughly and apply in small quantities around each tree be- 

 fore a soaking rain. 



The trees along a street should be evenly spaced at distances from 

 35 to 40 feet apart, irrespective of lot width and abutting property. One 

 prevalent mistake in tree planting is spacing them so closely together 

 than only straggling, crowded, unhealthy trees result. 



The trees should be placed opposite to each other if practicable, and 

 none should occur within 20 feet of the curb corner at street crossings, 

 in order that danger from collisions by vehicles may be lessened. 



On very narrow streets, however, the trees may be spaced alternately, 

 since they will thus have more growing space. 



Usually place trees between sidewalk and roadway. This arrange- 

 ment usually screens the pedestrians from the roadway and adds a feel- 

 ing of security. Occasionally in narrow streets the space or parking is 

 lacking for this arrangement and the trees must be placed between the 

 sidewalk and the buildings. 



Center parking containing one or two rows of trees according to 

 width is attractive where the street's width justifies. Often with a nar- 

 row center parking low shrubs, such as wild currant or spirea, is more 

 effective than trees. 



Only one species of trees should be used on any street, except where 

 the street is wide enough to permit four rows, in which case the two 

 inner rows may be composed of trees of one species and the two outer 

 rows of trees of a contrasting species. 



It is nearly as incongruous to line streets with an assortment of 

 species of trees as it would be to decorate a Greek temple with columns 

 of various orders. 



