STREET AND HIGHWAY PLANTING. 67 



it will do so and when these suckers gain any headway it is almost 

 impossible to eradicate them. Occasionally, if conditions are just right, 

 a very abundant crop of seedlings will appear, but this is not often, and, 

 as is the case with most seedlings, mortality is very high and the rest 

 can easily be destroyed. This feature of suckering is enough to black- 

 list the elm in many places, and is most noticeable in the case of the 

 cork elm (U. racemosa) and its varieties. 



THE CALIFORNIA LAUREL. 



This is a native tree (Umbellularia calif ornica) which occasionally 

 has been left on the parkings. Under advantageous conditions it 

 makes a very handsome tree. Since it usually grows along streams 

 and washes in the canyons, the trees often become top-heavy, produce 

 too many leaders and a very light root system, with the result that 

 heavy winds or rains often blow them down. Isolated trees have come 

 to our notice, which, on the other hand, have been kept to a single 

 leader and have been planted where they had to make a firm root 

 system. Here they have attained striking size and symmetry. 



Of course, it can be urged that the shade cast is very dark; that the 

 wood is at best rather brittle; and that the fruits are large and un- 

 pleasant underfoot. All of these are valid objections, but if the trees 

 are set far enough apart and in a position not subject to violent winds, 

 the first two can be, in a large measure, overcome. The latter has no 

 remedy. It is, perhaps, needless to note that the laurel makes its best 

 growth where there is considerable soil moisture, but not enough to 

 cause the formation of a superficial root system. 



This is a tree open for trial. It has not, as yet, been proven, and 

 we can only urge that plantings be made at some suitable place where 

 the public is willing to contribute to our general fund of knowledge 

 by a demonstration. 



The following lists are at best generalizations and as such are to be 

 used with extreme caution. A statement of fact in one locality may 

 be entirely without weight in another community. In using the 

 appended tables, the planter must compare the data given with actual 

 results as shown by trees in his neighborhood. It is impossible to 

 give lists which will hold for all parts of this State. We have here 

 considerable sectional variation in soil, temperature and moisture con- 

 ditions, as well as variations within the section. This latter may be 

 noted especially in soil and moisture conditions even in the length of- 

 a single street in some districts. 



Do not, therefore, accept the lists as final. Use them as a starting 

 point and modify as your conditions must demand. A few points 

 may be useful as guides in original work. 



1. If your summer temperature is high and humidity low, do not 

 use many deciduous species of eastern origin. Do not use conifers, 



