Japanese Rowan (Sorbus commixta) — identification, habitat & look-alikes

Japanese rowan is a small ornamental tree native to Japan, Korea, and nearby East Asia, prized for its glossy red-orange berries and deep purple-red fall color. In the US it's planted in landscapes in USDA zones 5 to 9, and it has in parts of the northern US and Canada. It's also sold as Japanese mountain ash.

Appearance

Growth form: A deciduous tree usually 20–33 ft (6–10 m) tall with a rounded crown, occasionally reaching about 60 ft (18 m).
Leaves: Feather-like compound leaves about 6–12 in (15–30 cm) long with 9 to 17 sharply toothed leaflets. They turn deep purple to red in fall.
Flowers: Small white five-petaled flowers in flat clusters 4–6 in (10–15 cm) across.
Flowering time: Late spring to early summer
Fruit: Glossy, bright orange-red berries about 5/16 in (7–8 mm) across ripen in fall; songbirds eat them.

Look-alikes

European rowanSorbus aucuparia

Check the winter buds: European rowan's are dark brown to blackish and covered with white hairs, while Japanese rowan's are smooth and hairless. Leaves, flowers, and berries look very much alike.

Why they get mixed upBoth are planted as ornamental mountain ashes in the northern US, with the same white flower clusters and red-orange berries.

Where it lives

Typical habitats: Mountain forests (native)
Gardens and parks
Range: Native to Japan, Korea, and Sakhalin in the Russian Far East. In North America it's grown as an ornamental and has escaped in some northern areas.
Preferred conditions: Does best in full sun and moist, acidic, well-drained soil. It handles wind but not salty coastal exposure.

Growing it

Care: Suited to USDA hardiness zones 5–9. 'Embley' is a cultivar with narrow, upright branching and later fall color. Watch for fire blight, scab, and borers, especially on stressed trees.
Propagation: Usually grown from seed.