ARBORICULTURE 



ARBORICULTURE 



357 



oughly firmed by tramping. Before the hole is com- 

 pletely filled, the tree should be well watered and the 

 remainder of the soil put in loosely. A strong stake 8 

 feet long should be placed beside the 

 tree- when planted. At least 30 

 inches of this should be in the 

 ground. The tree may be attached 

 to the stake by a piece of old gar- 

 den hose attached to each side of 

 tin- stake and put around the tree 

 in such a manner as to make a cross 

 between the stake and the tree. 



All young trees should be pro- 

 tected by boxes or guards. Many 

 forms are used! Any of them are 

 good if the box reaches from the 

 ground to a height of 5 feet and will 

 prevent horses biting the trunks 

 and boys swinging on the guard. 



Notes on ornamental 

 trees. 



Acer Negundo (box 

 elder). Too short- 

 lived, brittle and sub- 

 ject to insect attack. 

 Its use may be war- 

 ranted in semi-arid 

 and very cold regions. 



Acer pla tanoides 

 (Norway maple). 

 Moderate grower, 

 healthy , but too dense 

 for close city streets. 



Acer rubrum 

 (swamp maple, scar- 

 let maple). A good- 

 sized tree, good 

 grower, fine foliage, 

 especially brilliant in 

 autumn. Also a bright red in spring due to blossoms and 

 young leaves. Not suited to the interior of large cities. 



Acer saccharinum (silver maple, soft maple). Rapid 

 grower, but too brittle and short-lived, and the shallow 

 roots prevent the growth of grass under it and also 

 destroy sidewalks. 



Acer saccharum (sugar maple). Does not thrive on 

 heavy clay soils or under severe city conditions but most 

 excellent where it does grow. Moderate grower, doing 

 best north of the 40th parallel. 



Ailanthus oltissima (ailanthus, tree of heaven). 

 A large, handsome tree, the staminate and pistillate 

 flowers appearing on different trees, the latter very ill- 

 smelling. A most useful tree in the center of large 

 cities. The staminate form only should be planted. 



Celtis mississippiensis (southern hackberry). An 

 excellent tree in those regions in which the "witches- 

 broom" does not attack it. One of the promising trees 

 to withstand the hot winds of the plains as far north as 

 Denver. A large tree and good grower. 



Celtis occidentalis (hackberry). A good tree where 

 the disease known as "witches' broom" does not attack 

 it. It is for regions north of the 3fith parallel what the 

 foregoing species is for the region south of it. 



Fraxinus americana (ash, white ash). A good tree for 

 suburban conditions. Moderate grower, attaining large 

 size. 



Ginkgo biloba (ginkgp, maidenhair tree). An excellent 

 tree of peculiar pyramidal form when young. Moderate 

 grower, attains good size and is free from insect and 

 fungus attacks. 



dledilsia triacanthos (honey locust). A large, quick- 

 growing, handsome tree. Except for its thorns, this tree 

 would probably be a most desirable tree for the semi- 

 arid regions of the West. There is a thornless form that 

 may sometimes be obtained, which is good. 



316. Pinus ponderosa. 



Giant specimens 225 ft. high, grown in the deep, moist 

 soil of the Yosemite Valley. 



Liquidambar St^raciflya (sweet gum). A handsome 

 and valuable native tree but little used. Moderate 

 grower, good size, handsome fall coloring. A little hard 

 to transplant, especially in large sizes. Does not suc- 

 ceed well under extreme city conditions, and is not 

 adapted to the extreme northern sections. 



Liriodendron Tulipifera (tulip tree). Miscalled yel- 

 low poplar, and tulip poplar. A handsome, large, 

 quick-growing tree, little used, but valuable except for 

 extreme city conditions and much of the country north 

 of the 40th parallel. A little hard to transplant, espe- 

 cially in large sizes, and should be moved only in spring. 

 Magnolia grandijlora. A broad-leaved evergreen of 

 large size, adapted to the extreme South. A good lawn 

 tree as far north as Washington. 



Magnolia acuminata (cucumber tree). A handsome 

 tree of moderate size, good for suburban conditions 

 south of W'ashington and St. Louis. 



Magnolia tripetala (umbrella tree). A handsome tree 

 of moderate size, good for suburban conditions south of 

 Washington, and St. Louis. 



Melia Azedarach (umbrella tree). A small, attractive 

 tree, good for temporary effects from 

 North Carolina south and west. 



Nyssa sylvatica (sour gum, tupelo). A 

 large, handsome tree, adapted to subur- 

 ban conditions. Brilliant fall foliage and 

 winter berries. 



Plaianus occidentalis (sycamore, but- 

 ton wood). A large tree, rapid-growing, 

 open -topped, and almost scraggly in its 

 growth. Considered an untidy tree by 

 some on account of its seed-balls and the 

 bark which is shed in large flakes. The 

 white trunk, after the baik is shed, is 

 unusual and attractive. In some regions 

 it is subject to a blight just after the 

 leaves start in spring. A good tree for 

 severe city conditions. 



Platanus orientalis (plane tree, orien- 

 A more compact grower than the foregoing 



: 



tal plane). 



and a little better suited 

 to street purposes, but 

 not quite so rugged and 

 imposing as the fore- 

 going. An excellent street 

 tree. 



Populus deltoides, in- 

 cluding var. caroliniana 

 (cottonwood and Carolina 

 poplar). These two trees 

 are much used for street 

 planting in many places 

 but are entirely unsuited 

 for the purpose. Although 

 the growth of a severely 

 pruned tree is large in any 

 one year, it is the custom 

 to remove a half of this 

 each year so that the net 

 gam in growth is no more 

 than an average tree. Even 

 with this pruning it is liable 

 to be broken by a moder- 

 ate wind storm, and with- 

 out the pruning it is even 

 more liable to be broken. 

 Their roots are as bad as 

 willow roots about find- 

 ing and clogging sewers. 

 Wide-awake cities pro- 

 hibit the planting of these 

 trees. 



Populus nigra var. ital- 

 ici (Lombardy poplar). A 

 tall, short-lived, fastigiate 



317. Conifer forms Pine 

 and spruces. 



