Common Name: showy mountain ash, mountain ash
Scientific Name:
Family: Rosaceae
Genus: Sorbus
Species: S. decora
Hardiness Zone: 2 to 6
Height: 20 to 30 ft
Width: 15 to 20 ft
Common Characteristics:
Showy mountain ash, or also know as mountain ash is a small tree, typically 20-30 feet tall at maturity. It can be multi-stemmed. It has odd-pinnately compound leaves (up to 10 inches long) with 11-15 bluish-green to gray-green (2-4 inches) that are lanceolate in shape with serrate margins and pointed tips. Showy mountain ash produces densely clustered white flowers in the spring and clustered red fruits (pomes) containing 1-2 seeds each (3/8 inch in diameter) in late summer. The ripe pomes can cause the branches to droop downward. Fall color is yellow to red. The twigs are smooth, reddish-brown with lenticels and the buds are shiny, dark purple and with short hairs. The mature bark is smooth and gray or gray-brown in color with developing plates.
Where It Grows:
Showy mountain ash prefers full sun and acidic, moist, well-drained soils. It grows in cools areas like lake shores or mountains. It is slightly intolerant of urban pollution.
How It's Used:
Mountain ash is often used in small landscapes as a decorative lawn tree or as a shade tree because of its small size and showy flowers and fruits. It requires little pruning, which can be done from late fall to early spring. This tree is good for bringing birds to the landscape.
Ecosystem Services:
Birds and small mammals will eat the fruits.
Where It Is Native To:
Its native range is from Canada (Labrador, Newfoundland, Quebec) to the northeastern United States (Iowa, New York, Maine). Some populations reach North Carolina.
Problems:
Problems that mountain ash can have are bacterial fireblight, scab, cankers, crown gall, powdery mildew, rust, and borers.
Other Details:
Although it is not in the ash family (Fraxinus), the common name showy mountain ash is due to its leaves which look like ash leaves.
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