The species glandulosa, the Tree of Heaven, is a small deciduous tree grown for its handsome foliage. It is hardy, but strong, cold winds may impair the leaves and consequently it should be planted in a sheltered place. It does well in towns. Where sub-tropical gardening is practised the Ailantus may be cut to the ground in spring if the soil is deep, fertile and moist, as it will then produce splendid foliage. The shoots should be thinned to one. Giraldii has large compound leaves.
See Chapter 18.
The common Alder is Alnus glutinosa, and it is useful because it will thrive in swampy places. Several varieties of it are offered, of which the most popular is aurea (foliis aureis) with yellow tinted leaves. Crispa and laciniata are other varieties.
One of the earliest blooming of deciduous trees, sometimes flowering as early as February. The beauty of the bloom is not injured by frost, and the only effect is that the fructifying organs are injured, so that the tree rarely develops fruit in Britain. The Almond belongs to the genus Prunus, to which reference should be made for the best species. Chapters 9. and 26. also contain references to it. Although the Almond likes a light soil, it is not fastidious. It thrives in suburban gardens.