CHAPTER XXIII 



FAST-GROWING TYPES VALUABLE FOR PRODUCING 



SCREEN EFFECTS 



It often becomes necessary to find some fast-growing type of 

 tree or shrub to produce an immediate screen. This is especially 

 true in the development of new landscapes where a foliage effect 

 is desired and the more permanent types of shrubs in the planta- 

 tion require a longer period to produce the desired effect. In such 

 instances the more rapid-growing types of shrubs may be planted and 

 removed after the first one or two years, at which time the more 

 permanent types have developed far enough so that during the suc- 

 ceeding years they will produce the effect which the designer had in 

 mind when they were first selected. The great danger in using quick- 

 growing types of temporary materials for immediate effects lies in the 

 fact that for the success of such plantations the owner must have the 

 "courage of his convictions" and remove the temporary types of 

 material when the time comes that they are beginning to crowd and to 

 injure the more permanent types. 



In other instances, where it is necessary to screen service buildings 

 or blank walls of other buildings such quick-growing types of trees 

 and shrubs as the ailanthus, poplars, willows, and elders may be planted. 

 The ailanthus especially is used to form a mass of foliage against 

 service buildings and blank walls during the summe rmonths, but 

 this tree is cut back each year to a height of three or four feet and the 

 new growth produces the effect during the next year. 



The fast-growing types of trees and shrubs often used to produce 

 quick effects are correspondingly short lived. Those trees and shrubs 

 which grow rapidly, mature and decay nearly as rapidly. Very few 

 of these types should be placed in permanent plantings. 



This list consists of two distinct groups of fast-growing material: 

 that group of which the ailanthus, poplar, willow, and elder are typical, 

 being the very rapid-growing types of material, and that group of which 

 the remaining trees and shrubs are typical being rapid-growing types 



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