Distinctive bark, attractive leaves and manageable size make birch trees an excellent choice for the landscape. There are a number of varieties with variations in foliage, bark and cultural needs. These trees are relatively pest-resistant and hardy, but with the right cultivar selection a birch can be grown in almost any yard.
Betula lenta (sweet birch) is native to much of the eastern United States. The bark is very different than that of other birches; initially red, then peeling in brownish layers that eventually change to black. Betula lenta has leaves and twigs that give off a strong smell of wintergreen when crushed. This is a good shade tree, growing up to 40 feet, and has yellow fall color. It's hardy in USDA zones 3 through 9.
Betula nigra (black birch) has the stereotypical peeling bark of the birch family in a wider range of colors. Bark layers peel away, revealing tones of white, cream and rust. Betula nigra is very tolerant of a wide range of soils, and is drought-resistant once established. "Heritage" has the most attractive bark coloration, and good disease resistance. Fall color is yellow. It's hardy in zones 4 through 9.
Betula pendula "Laciniata" (cut-leaf weeping European brch) displays unusual deeply cut leaves and a graceful, pendulous form. The eventual growth of this tree depends on availability of water. Areas with high moisture levels will produce a specimen up to 50 feet tall. Places consistently dry during the main growing season will grow trees to 30 feet. This tree will withstand quite a bit of smog and pollution, but its eventual height may make it inappropriate for a small city yard. It's hardy in zones 2 through 9.
Betula utilis "Jaquemontii"' (paper bark birch) grows into the classic birch form, with creamy white peeling bark and delicate green foliage. This tree will grow in most soils and is hardy in zones 3 through 9. Bark coloration can be slow to develop, with young trees having no hint of white the first few years.
The main problem with birch trees is their short lifespan. Some may decline and die after only 20 years. Providing good soil, regular water and monitoring for disease and insect problems will go a long way in extending the longevity of the tree.
Birches require full sun, but their roots should be cool and shaded. On young trees, the root system is so shallow even a small period of drought can damage them. Mulching around the trunk of the tree out to the drip-line and planting shallow rooted shrubs and perennials will help keep roots shaded and evenly moist.
In areas with very wet soils, avoid planting the white bark birches. Betula nigra has a similar look, and will grow in heavy soil and even survive brief submersion.
Birches are on the whole very disease-resistant. Anthracnose can be a problem in some areas, however. This disease causes unsightly mottling and curling of the leaves. Primarily cosmetic, it will rarely kill the tree. An anthracnose episode followed by a drought or an insect infestation will cause serious problems and eventual death. Properly monitoring water levels and mulching the roots will provide the conditions birches need to thrive, lessening the chance of disease.
Insects that commonly infest birches include the birch borer beetle, birch leafminer, and aphids. The birch borer is the most serious pest, causing decline and death even in mature trees. Birch leafminers primarily disfigure leaves, and do not cause any lasting damage. Aphids usually afflict new growth, causing the leaves to curl. A strong spray of water will dislodge them. Borer beetles can be controlled with an insecticide applied to the trunk, although this is not always effective. Maintaining the health of the tree through good cultural practices is more useful and longer lasting.
Birches can be used as a single specimen, or be planted as a group. Single specimens of Betula nigra are very beautiful, with their multicolored bark and large leaves. Betula utilis looks stunning planted as a group, the white trunks providing contrast with other landscape elements. Shrubs and perennials to be interplanted with birches should have low water needs and tolerate partial shade. Take into account that the tree may have to be removed within 30 years, and plant in an area that is easy to access.