Arboriculture and Ornamental Planting 261 



form that will please the eye, and be long lived. If a 

 shade tree, it must have dense enough foliage to produce 

 a solid, cool shade and not have merely enough leaves to 

 stop the breeze and let through the heat of the sunshine. 

 Moreover, the branches must be long, low and widespread- 

 ing enough to furnish a considerable area of shade. It 

 must be free from the attacks of insect pests that in the 

 form of dropping bugs or caterpillars would make its pro- 

 tection unpleasant. It must be "clean" ; that is, it must 

 not shed excessive quantities of cotton, leaf stems or twigs 

 on the lawn. It must not bear soft, squashy berries or 

 other similar fruits. The trees which fulfill all these 

 requirements are not very numerous ; there are, however, 

 good species for every region. 



Trees for roadside planting or bordering a driveway need 

 not possess all these properties ; in fact, some of them are 

 undesirable. They must not have low, widespreading 

 limbs, but rather limbs that rise at a sharp angle so that 

 they are widespread only at a considerable distance above 

 the ground. Neither soft fruit or leaf litter are objec- 

 tionable, but falling limbs and cotton are as undesirable 

 here as elsewhere. They should also be long lived. Such 

 trees form over the drive a high arch which is very attrac- 

 tive. They should be rapid growers, for the effect is not 

 appreciated until the trees are large. 



In the formation of groups or clumps, the most impor- 

 tant point is the ability of the trees to grow in close forma- 

 tions. For this purpose, trees are selected that are very 

 tolerant of shade. They should always be of rather com- 

 pact form, and have the habit of branching down to the 

 ground. This adds density and solidity to the appearance 



