European mountain ash (Sorbus aucuparia)

First place champion European mountain ash in Glenwood Springs.

Species info:

Leaves: Alternate, pinnately compound, with serrated medium to dark green leaflets. Fall color ranges from yellow to orange-rust to reddish purple.

Leaflets: Typically 11–17 per compound leaf, each 1–3 inches long, finely serrated.

Leaf Surface: Smooth above, slightly paler beneath.

Bark: Attractive golden-amber to gray-brown, with prominent pale lenticels; becomes slightly scaly with age.

Flowers: Small, white, fragrant clusters (3–4 inches across) appearing in May after leaf-out.

Fruit: Small (¼ inch) orange-red pomes in dense clusters; some cultivars bear red, yellow, orange, or pink fruit. Fruit often bends branches under its weight and is relished by birds. Edible for humans and used in syrups, teas, or preserves.

Botanical: Sorbus aucuparia

Family: Rosaceae

Mature Height: 25–35 feet

Canopy Spread: 15–25 feet

Foliage Type: Deciduous

Tree Shape: Upright-oval to rounded form

Growth Rate: Medium

Fruit: Primarily ornamental, but is edible

Flower: Showy

Fall Color: Yellow to red or rust-orange

Water Use: Moderate; prefers moist, well-drained soils

Hardiness: Best in Zones 4–6 (in Colorado, performs well up to 7,500 ft)

Soil Preference: Moist, well-drained, acidic to mildly alkaline soils; struggles in dry or compacted clay

Wildlife Value: Fruit provides food for many bird species, especially waxwings and robins

Pests/Pathogens: Aphids, pear slugs, and borers (especially under stress); fireblight, cytospora canker, leaf rusts, sunscald.

Planting Recommendations: Recommended for most sites, but due to susceptibility to fireblight should be avoided in lawns; for best performance plant on east or north exposures in mulched, irrigated sites and avoid hot, dry southern or western exposures

Information Sources:

• Front Range Tree Recommendation List

• Michael Dirr, Manual of Woody Landscape Plants (University of Georgia, 1990)