VI L iotu in Blast! 



A Setatlrii (Eonattorattmt of (Urourinn, (Eonottinns anh Planting 



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It is only when we come to consider the actnal details of 

 planting that we find, as suggested in Chapter II, the diffi- 

 culties which beset successful tree growth in Manhattan. 

 The problems which must be solved, in addition to those nor- 

 mally met in street tree culture such as protection against 

 physical injury and the ravages of insects and disease, are 

 of two general classes : 



(I) Those which pertain to securing and maintaining 

 correct soil conditions. 



(II) Those which pertain to securing and maintaining 

 correct crown conditions. 



The latter consist principally in adjusting the size of the 

 crown to the available sidewalk widths and to the capacity 

 of the roots in their restricted soil areas. Such problems 

 can largely be solved by correct pruning which is not diffi- 

 cult to secure. 



. By keeping a perfect balance between the top growth and 

 the root system one may often secure a successful street tree 

 even when soil conditions are generally bad and where a 

 large-sized tree would almost certainly fail. 



A correct adjustment of the tree shade for any street to 

 the supply of light and air necessary for the lower stories of 

 the buildings upon the street depends largely upon the 

 sidewalk width and the planting design. There can be no 

 question but that limiting top growth by severe pruning is 

 often advisable for reasons of health and hygiene as well 

 as for the aesthetic reason of improving the design and 

 the purely horticultural reason of securing successful 

 growth. This matter has already been mentioned in 

 Chapter IV. 



(55) 



