320 



Bulletin 256. 



vitality or they are certain to meet with an unnatural and premature 

 death. Only a very small percentage of the trees used for city work 



^^^^^^ are of the species best adapted to withstand the 



V &W^M conditions. 



A scarcity of water from the surface, together with 

 an abundant supply from the subsoil, fosters the 

 production of deep-seated roots, which are one of 

 the most valuable assets of a good shade tree. On 

 the other hand, a thoroughly water-clogged soil ad- 

 mits no air circulation, and increases the tendency 

 to the development of surface roots, which are 

 killed during periods of drought; it also provides 

 avenues for root diseases, and finally leads to the 

 death of the tree. Poor soils bring about the con- 

 dition often known as "stag-head," the symptoms 

 of which are a stunted and sickly appearance of the 

 tree, the presence of slender and weak branches, 

 and a sparsely scattered yellow foliage. The remedy 

 for such a condition depends on its stage of devel- 

 opment when detected. In its early 

 stages, the tree may be rejuvenated 

 by digging out a quantity of the 

 Fig. 2sg.— Injuries P°°^ soil and replacing with good 



resulting from the loam; if the specimen shows too 



gnawing of horses ,^^ ^ ^^ ^^ ^^ weakness, it had 



during the early li}e ° , ° . 



of a tree. better be substituted by a younger, 



vigorous specimen. The Shade Tree 

 Commissioners of Newark, N. J., by means of a small 

 leaflet that they distribute to all prospective tree plant- 

 ers of the city, have accomplished results in partially 

 guarding against the starvation of root systems (see 

 Fig. 241). They require that all holes for newly planted 

 trees shall be of a certain size and filled with good loam 

 in which the roots can feed, and also that a certain open 

 space shall be left around the base of each tree for the 

 entrance of water to the roots. This space is often four 

 feet square, or sometimes rectangular, the long side of 

 the rectangle being parallel to the sidewalk line. Through 

 these open spaces the trees are watered and fertilized 

 when necessary. To prevent the trampling of the earth about the base 

 of the tree, the open space is almost always covered with a movable 

 iron grating (see Fig. 242). 



Fig. 240. — Shozu- 

 ing the method of 

 preserving a tree 

 that has been ser- 

 iously injured by 

 horse bites. 



