Korean Mountain Ash
Sorbus alnifolia

Family: Rosaceae (ro-ZAY-see-ee) (Info)
Genus: Sorbus (sor-bus) (Info)
Species: alnifolia (al-nee-FOH-lee-uh) (Info)

Category:

Trees

Height:

over 40 ft. (12 m)

Spacing:

30-40 ft. (9-12 m)

Hardiness:

USDA Zone 3a: to -39.9 C (-40 F)

USDA Zone 3b: to -37.2 C (-35 F)

USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

Sun Exposure:

Sun to Partial Shade

Danger:

N/A

Bloom Color:

White/Near White

Bloom Time:

Mid Spring

Late Spring/Early Summer

Foliage:

Grown for foliage

Deciduous

Smooth-Textured

Other details:

This plant is attractive to bees, butterflies and/or birds

Average Water Needs; Water regularly; do not overwater

Soil pH requirements:

5.1 to 5.5 (strongly acidic)

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:

Non-patented

Propagation Methods:

From softwood cuttings

From seed; direct sow outdoors in fall

From seed; winter sow in vented containers, coldframe or unheated greenhouse

By grafting

By budding

Seed Collecting:

Allow unblemished fruit to ripen; clean and dry seeds

Regional

This plant has been said to grow in the following regions:

Baton Rouge, Louisiana

Buckfield, Maine

Roslindale, Massachusetts

Grand Marais, Michigan

Minneapolis, Minnesota

Lee, New Hampshire

Cincinnati, Ohio

Nellysford, Virginia

show all

Gardeners' Notes:

3
positives
0
neutrals
1
negative
RatingContent
Positive

On Mar 18, 2014, coriaceous from ROSLINDALE, MA wrote:

There's a beautiful mature specimen in the Arnold Arboretum, Boston, MA Z6a that never shows any problems. Excellent form, grows large (to 50'). A beautiful 4-season shade tree.

Showy white May flowers, though in mature trees they're up high in the canopy. Gold to scarlet fall color can be outstanding. Showy scarlet fruit holds late into the winter, till the birds take them, and beautiful silvery beech-like bark.

Most mountainashes are small, short-lived trees, but this species is resistant to borer, lives much longer, and grows much larger than the others here in eastern Massachusetts.

This species is one of the Elizabeth Cary Miller Botanical Garden's Great Plant Picks, designed to promote the best plants for gardens of the maritime Pacific N... read more

Negative

On Mar 18, 2014, Zipity11 from Brentwood, NH wrote:

Very invasive. We cut down the 44 trees in our Alle.

Positive

On Oct 19, 2011, NancyMcD from Grand Marais, MI wrote:

This fine tree has done well for us here on the south shore of Lake Superior. It is rather slow-growing, like all mountain ashes (perhaps ten feet in ten years). The foliage is handsome in three seasons. You do need to protect it from deer in winter until it's tall enough to manage on its own. We pound in steel fenceposts and wrap snow fencing around it each fall and remove them in the spring. The tree is well worth the effort.

Positive

On Mar 2, 2008, Malus2006 from Coon Rapids, MN (Zone 4a) wrote:

This is a underused species that is offered rarely in the plant trade. For the most part, it look like any other Mountain ash. The difference is into its leaves which look like Beech! The famous plant author, Michael Dirr said that this is the best of the Mountain Ash Species!