THE ORNAMENTAL PLANTS — TREES 321 



of the tree at the base, for a tree that is covered a foot or two above 

 the natural line is not only in danger of being killed, but it 

 looks like a post. 



The best shade trees are usually those that are native to the 

 particular region, since they are hardy and adapted to the soil 

 and other conditions. Elms, maples, basswoods, and the Hke 

 are nearly always reliable. In regions in which there are seri- 

 ous insect enemies or fungous diseases, the trees that are most 

 likely to be attacked may be omitted. For instance, in parts of 

 the East the chestnut bark-disease is a very great menace; 

 and it is a good plan in such places to plant other trees than 

 chestnuts. 



A good shade tree is one that has a heavy foliage and dense 

 head, and that is not commonly attacked by repelling insects 

 and diseases. Trees for shade should ordinarily be given suffi- 

 cient room that they may develop into full size and symmetrical 

 heads. Trees may be planted as close as 10 or 15 feet apart for 

 temporary effect ; but as soon as they begin to crowd they should 

 be thinned, so that they develop their full characteristics as 

 trees. 



Trees may be planted in fall or spring. Fall is desirable, 

 except for the extreme North, if the land is well drained and pre- 

 pared and if the trees may be got in early; but under usual con- 

 ditions, spring planting is safer, if the stock has been wintered 

 well (see discussion under Shrubs, p. 290). Planting and 

 pruning are discussed on pp. 124 and 139. 



If one desires trees with conspicuous bloom, they should be 

 found among the magnolias, tulip trees, koelreuteria, catalpas, 

 chestnuts, horse-chestnut and buckeyes, cladrastis, black or 

 yellow locust, wild black cherry, and less conspicuously in the 

 lindens; and also in such half-trees or big shrubs as cercis, 

 cytisus, flowering dogwood, double-flowered and other forms 

 of apples, crab-apples, cherries, plums, peaches, hawthorn or 

 Crataegus, amelanchier, mountain ash. 



