PLANriNG DESIGN _ 153 



Closeness of texture, symmetry of shape, similarity of plant to Relation of 



plant, may be continued for a lone while under good maintenance, or 



111 -i -ri t - i i i r Dfsign and 



quickly lost without it. Plants or varying robustness and speed ot Maintenance 



growth may thrive together under good maintenance, but otherwise 

 the stronger soon destroy the weaker. Plants may be set out close 

 together for immediate effect, and good effect be later maintained if 

 they be thinned at the appropriate time. If this future thinning cannot 

 be relied on, either present or future effect must be sacrificed in the 

 planting. Design will therefore often depend on the degree of mainte- 

 nance that can be expected. 



The characteristics of plants, over which, as we have seen, the Plant 



landscape architect has little or no control, have inevitably a great in- Characteristics 



in Landscape 

 fluence on the effect of any design in which vegetation is used as a Design 



material. The forms, colors, and textures offered by plants give to the 

 designer certain opportunities, but also they set for him certain limits. 

 The natural character of each plant, and the associations which in 

 most men's minds cling to certain plants, give a plant a complex in- 

 dividuality, and make it by no means an easy thing to use in esthetic 

 composition. The understanding of these characteristics of plant 

 material constitutes no inconsiderable part of the skill of the landscape 

 architect. Indeed, it is special knowledge like this which differentiates 

 the landscape architect from other designers. 



In the forms of trees and shrubs and herbaceous plants with which Plant Forms 

 the landscape architect deals there is a very great variety. The forms 

 are similar only in the fact that they are all the expressions of the growth 

 of the individual plant, and that they are all more or less symmetrical 

 on a central axis. From the physical necessities of their growth, plants 

 are balanced forms, either a mass of foliage upon a central stalk, or a 

 number of separate branches diverging more or less consistently from 

 the vertical, and forming a typically symmetrical mass of leafage as 

 each twig and leaf equally seeks the light. Almost any free-standing 

 plant, not distorted by some unusual influence, will be, therefore, as far 

 as shape goes, an individual and self-sufficient object in the composition. 

 The same general considerations as to the use of these forms in compo- 

 sition apply equally to all kinds of plants, but with herbaceous plants,* 



* See discussion of herbaceous border and flower beds later in this chapter. 



