The mountain ash is an ornamental tree that actually belongs to the same family as rose bushes. Some mountain ash trees have a shrub-like form, while others can reach up to 50 feet tall. Mountain ash is known as rowan in Europe. The mountain ash offers an attractive form to landscapes with pretty flowers in spring and vivid color in the fall.
The American variety of mountain ash, Rosaceae Sorbus, has alternate, pinnately compound leaves that grow to 2 to 2-1/2 inches long with a dark green upper surface and lighter underside. The bark is smooth and grayish brown when the tree is young but tends to develop cracks and scaly patches with age. The lacy leaf crown spreads with age, providing dappled shade for yards.
Range of Distribution
Mountain ash can be found throughout the northeastern part of the United States, parts of the southeastern United States, mid-Atlantic states, upper Midwest and well into Canada. It is a native plant in North America and is often planted beyond its naturally occurring range. Mountain ash is hardy in USDA hardiness zone 2 to 5.
The mountain ash produces 3 to 5-inch clusters of showy, white flowers in late spring and into early summer. These develop into small, ¼ to 3/8-inch bright, red berries that ripen in the fall. Berries are a food source for birds and other wildlife.
Mountain ash trees turn a vivid orange to purple color in the autumn months, making it an attractive choice for residential landscapes.
The berries of the mountain ash are very acidic and do not make good eating for humans, but they can be cooked and made into a jelly. They can also be made into wine. In past ages, the berries were distilled into a kind of beer. Mountain ash berries contain high levels of vitamin C and can be used to prevent scurvy. A tea made from the berries was once used to treat urinary infections and diarrhea. Wood from the mountain ash is known for its durability. It was often used for tool handles, walking sticks, furniture, beams and wood planks.
Mountain Ash Care
Mountain ash grows well in full sun or partial shade. It prefers an acidic, well-draining soil. Mountain ash can suffer from overwatering, so allow the soil to dry out well before irrigating. Prune the mountain ash to eliminate multiple trunk stems. Mountain ash does not do well in areas with heavy road salt and pollution. Small animals that gnaw on the bark can cause significant damage to the tree.