90 STREET AND HIGHWAY PLANTING. 



than any expense at first hand. Fig. 47 shows the appearance of a 

 grill from the surface and in section. 



All trees, of course, receive a thorough watering at the time of their 

 planting, but there must be systematic watering after that. It has been 

 found that it does not pay to leave watering to the individual property 

 owners. At best they are prone to forget, and if the trees will show 

 difference of treatment there will be irregularity in the planting which 

 will mar the whole effect. 



To prevent this it is desirable to have the watering done by the city. 

 If the city takes charge the expense is kept down, and a systematic 

 treatment is assured. During the first three years of the tree's life on 

 the streets it must be watered with the greatest care. After its first 

 watering it is usually watered every two or three weeks during the 

 summer until the winter rains begin. The second year once a month 

 will suffice, and, in some cases, every other month. The third season 

 is usually confined to helping along the backward trees, with water for 

 the others if necessary. Palms very often need it during a third season. 

 Backward trees and trees which show irregular growth, as camphor or 

 live oak, must have more frequent and more copious waterings than the 

 normal specimens or more even growing species. Also, trees in situa- 

 tions which are more exposed or which are in soil which does not retain 

 its soil mosture freely, need special attention. 



The amount of water to be given to each tree varies according to 

 many factors. Trees after planting need more than established trees; 

 trees with shallow roots need more than deeply rooted trees; trees in 

 very porous soil need more moisture than normal soils, and certain 

 species need more than others. A case in illustration of the last point 

 will be found among the acacias. Acacia melanoxylon will use all the 

 water obtainable, while A. decurrens dealbata will suffer Avith the same 

 amount and thrive with less. Every one would realize that a magnolia, 

 a liriodendron or a sequoia would want more moisture than a eucalypt 

 or a desert palm. 



So far very little has been done in the way of fertilizing and culti- 

 vating the street trees. So far as was noted, but one case of artificial 

 fertilization was seen. This case was a planting of acacias on a poor 

 soil which was very rocky. The fertilizer used was barnyard manure 

 mixed with the soil from the four-foot hole. Certainly these trees gave 

 no evidence of poverty of soil. Similar instances have been found for 

 individual trees which do not mature rapidly. Chemical fertilizers, 

 chiefly mixtures of acid phosphate and muriate of potash, have been 

 tried in the East with good results, but no records are at hand for their 

 use here. Occasionally street sweepings are saved and incorporated 

 with the soil, but their action is often as much physical as it is chemical. 



