84 
EASTERN SHADE TREE CONFERENCE 
been made without due regard for soil preparation, the suitability of 
the tree for the situation or the part they would play in a city-wide 
street tree system. The resulting effect is a lack of uniformity, an 
injurious crowding, and a generally poor, weak growth which requires 
an immense burden of maintenance. Approximately one-third of the 
trees are in a poor condition. Inadequate forestry practice in the past 
has left a heritage of badly pruned and undernourished trees. Practi¬ 
cally no street tree in the city reaches maturity and the average life span 
is under twenty years. Most of our streets are not designed to receive 
trees. Many trees have been planted at ten foot intervals especially 
where the lots are only twenty feet wide. Poplars and Silver Maples, 
both fast growing and weak wooded types which are undesirable, have 
been freely planted and in sections of Brooklyn and Queens they pre¬ 
dominate. In many districts, especially in Manhattan, the ground 
under the streets is either rock or sub-structures. Buildings and pave¬ 
ments seal the surface of the ground from air and rainfall. The atmos¬ 
phere is seriously polluted and with a weakened growth plus vandalism 
and escaping gas, the trees are likely subjects for diseases and insect 
depredations. 
The difficulty of maintaining trees in New York City is probably 
greater than in any other city. To simulate the tree lined Boulevards 
of Paris or Washington would require a constant replacement program 
of great proportions. In recognition of the unnatural growing condi¬ 
tions created by poisoned atmosphere; terrific reflected heat; soils low 
in humus content, frequently high in the acidity range, and with 
nutriment values spent, it is a wonder that trees live at all. The 
least provision that can be made is a generous supply of fertile soil and 
plant foods. A volume of soil not less than cubic yards, to a depth 
of at least 3 >2 feet, should always be provided. The surface opening 
should not be less than 15 square feet. A program of laying Belgian 
blocks instead of an iron grating has been adopted in the city with good 
success. It serves to prevent the compacting of the soil over the roots, 
their sand filled joints permit the entrance of surface water and the 
stones act as a beneficial agent in conserving moisture and protecting the 
roots from rapid changes in temperature. 
The so-called Oriental Plane tree, really the London Plane, Platanus 
acerifolia, is definitely the best street tree for this city although it is on 
the border line of hardiness in this latitude. Positive injuries were sus¬ 
tained by this species during our recent severe winters. The Maidenhair 
