When planting trees either as ornamentals or as part of a windbreak, it's important to plant varieties that are drought resistant, particularly in the midwestern United States. Hot summers with infrequent rainfall can stress trees that need consistent moisture. Trees planted in the Midwest should also be hardy enough to withstand the brutal winter temperatures throughout much of the region.
A long-lived hardwood tree, green ash (Fraxinus pennsylvanica) is a particularly drought resistant variety of the ash genus and is the most widely planted variety of ash in the Midwest. It grows 50 to 60 feet tall with an upright habit when young that develops into a rounded shape as it matures.
Female trees are only used in windbreaks because of their prolific re-seeding of weed trees after they drop their seeds. Male varieties are grafted and sold to eliminate this. The green ash will survive winter through USDA hardiness zone 3.
With a form similar to the now rarely planted elm tree, the hackberry (Celtis occidentalis) grows quickly to a height of 50 to 60 feet. It prefers moist, fertile soil and develops a deep root system, which helps it tolerate drought conditions. Hackberry is not bothered by any serious diseases.
Foliage is medium green and turns yellow in autumn. Small green berries develop in summer and turn deep purple in late summer or early fall. Planted as a shade tree, for windbreaks and along city streets, it's reliably hardy through USDA zone 4 and under trial in zone 3.
A member of the legume family, black locust (Robinia pseudoacacia) produces pea-like flowers in long clusters in early June. The cream-colored flowers have the trademark sweet pea fragrance.
Black locust trees seldom grow to their full mature height of 50 feet because of damage by locust borers, which weaken the trunk. The weakened tree then falls over in high winds. The root system often produces many suckers. It's hardy as far north as USDA zone 3.
Russian olive (Elaeagnus angustifolia) can be grown as a small tree or a large shrub. Although technically not an olive, it has a similar appearance. Fragrant yellow flowers bloom in June, followed by silvery, small, plum-like fruits. Although drought resistant, it does not tolerate soils that are poorly drained. Its silvery foliage makes it an ideal addition to windbreaks or as a background or specimen planting. It's hardy through zone 3.