STREKT AM) IIKHIWAY PLANTING. 15 



about bad conditions on the road or highway. But of this question of 

 deciduous versus evergreen species, more later. 



Spacing often spoils a good tree. A case in point is the frequent use 

 of Acacia melanoxylon. This is an excellent tree in many ways. Its 

 natural mode of growth is symmetrical and fairly rapid ; the scale insects 

 which attack it rarely produce serious effects ; it lives to a considerable 

 age and throughout its existence needs but little attention to pruning ; 

 it is fairly free from litter and is indifferent to cultural conditions. 

 Here is a tree with a desirable set of qualifications which in almost every 

 case is planted in such a fashion that it becomes very undesirable. 

 When planting this acacia it should be borne in mind that it is an ever- 

 green of a green black color and of a density of growth which produces 

 a very intense dark shade. Moreover it is a tree which needs abundant 

 room for development. This fact is one which is frequently overlooked, 

 since we can find many instances where it is set at intervals of some 

 twenty-five or thirty feet so that a solid hedge of trees has developed, 

 completely shutting off the sun from the houses behind them until 

 about noon. Furthermore, any air that may be in circulation is effectu- 

 ally shut off. The solution of the problem is easy.. If one feels that 

 Acacia melanoxylon is necessary to his happiness, buy specimens that 

 are headed high; prune out enough branches to keep the head from 

 being too dense and plant at least fifty fe'et apart, preferably alternat- 

 ing across the street. In the case of very wide streets, this last precau- 

 tion is, of course, unnecessary. 



The question of litter is no small matter in the appearance of the 

 city. And the tree which is untidy should have no preference over less 

 annoying trees in the scheme of civic decoration. A case of a very 

 common malefactor is the ever popular umbrella tree (Melia azadarach). 

 This tree, which is almost invariably headed too low, causes a litter in 

 the spring at flowering time ; in the autumn the leaflets drop ; then the 

 petioles, and last of all intermittently through the winter the berries 

 and the panicles that bore them. Here we have a case of constant 

 litter for about two thirds of the year, which certainly outweighs the 

 possible beauty of foliage or flower. Another instance is the grevillia, 

 where the litter from falling leaves and broken branches is quite 

 incessant. 



And last, but not least, from the practical and economical standpoint. 

 is the longevity of the tree. The desire for immediate effect often over- 

 throws proper discretion. Most of the trees which will give quick 

 results, for example, the umbrella tree, the Carolina poplar, the silver 

 maple, Acacia pycnantlia, Acacia retinodes and many more, do not give 

 permanent or lasting results, and the effort spent on them is quite 

 wasted. Then, when they have reached maturity and fallen into decay. 



