A Street Tree System for New York City 75 



the knowledge of the differing local conditions some degree 

 of basic comparison may be made. 



In estimating the cost of street tree control in Manhattan 

 it is necessary to note first the cost for the trees which are 

 to be maintained, both existing and proposed, and second the 

 cost of the new planting. The system of street tree planting 

 which is outlined on the map accompanying this report pro- 

 vides for approximately eighty-five miles of planted streets 

 which would give, at the rate of 200 trees to the mile (the 

 number secured by following the spacing arrangement of our 

 proposed block planting plans), approximately 17,000 trees. 

 There is perhaps a street mileage half as great which is not 

 included in the system, but upon which street trees may be 

 grown successfully if desired (i. e., streets purely residential 

 in character, lying in the proposed restricted residential 

 districts), Assuming 8,000 trees to be the number required 

 for such streets we get a total of 25,000 trees as the number 

 of street trees which may be ultimately secured in the 

 Borough of Manhattan. 



The street tree census, which was completed by the 

 writer as far north as 110th Street, recorded 5,400 trees. 

 From a careful examination of the balance of the Borough, 

 it would seem that a reasonable estimate would place the 

 number of street trees south of 110th Street at about one- 

 third of the entire number in the city, so that an estimate 

 of 15,000 is a fairly accurate one as to the number of exist- 

 ing trees upon Manhattan streets. Bully two-thirds of these 

 existing trees are, however, in a very unsatisfactory condi- 

 tion, and probably not more than 5,000 can be considered a 

 part of our permanent planting. 



Our problem thus becomes the preservation of the 5,000 

 existing trees which are of permanent value, and the re- 

 placement of the 10,000 inferior or deteriorating trees, 

 together with the planting of an additional 10,000 new trees 

 on streets not now planted. Our maintenance operations 

 will therefore begin with the total of 15,000 trees which, 

 allowing for the removal of dead and dying specimens, may 

 be considered to be increased each year by one-half the 



