Sorbus alnifolia (Korean mountain ash)

Botanical name

Sorbus alnifolia

Other names

Korean mountain ash, Korean whitebeam

Genus

Sorbus Sorbus

Species

S. alnifolia - S. alnifolia is a broadly conical, deciduous tree with ovate, to lance-shaped, toothed, dark green leaves turning red, orange, and yellow in autumn and dense corymbs of small white flowers in mid-spring followed by spherical red to dark pink fruit.

Foliage

Deciduous

Habit

Broadly conical

Toxicity

Fruit may cause stomach upset.

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Colour

Flower

White in Spring

Foliage

Dark-green in Spring; Dark-green in Summer; Yellow, Orange, Red in Autumn

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How to care

Watch out for

Specific pests

Aphids , Blister mite , Sawflies

Specific diseases

Apple and pear canker , Fireblight

General care

Pruning

Pruning group 1.

Propagation methods

Budding, Grafting, Softwood cuttings

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Monthly care advice

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Where to grow

Sorbus alnifolia (Korean mountain ash) will reach a height of 20m and a spread of 8m after 10-20 years.

Suggested uses

City, Cottage/Informal, Low Maintenance, Specimen tree, Wildlife

Cultivation

Best in moist but well-drained, acid soil in full sun. Suitable for cool climates. Does not do well in heat and humidity. Dislikes urban pollution.

Soil type

Chalky, Loamy, Sandy

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Acid, Neutral

Light

Partial Shade, Full Sun

Aspect

South, East, West

Exposure

Exposed, Sheltered

UK hardiness Note: We are working to update our ratings. Thanks for your patience.

Hardy (H4)

USDA zones

Zone 7, Zone 6, Zone 5, Zone 4, Zone 3

Defra's Risk register #1

Plant name

Sorbus alnifolia (Korean mountain ash)

Common pest name

grape ground pearl

Scientific pest name

Margarodes vitis

Type

Insect

Current status in UK

Absent

Likelihood to spread to UK (1 is very low - 5 is very high)

2

Impact (1 is very low - 5 is very high)

5

General biosecurity comments

Main pathway; Vitis spp. plants for planting; already prohibited. However; further consideration of other pathways is required.

Defra's Risk register #2

Plant name

Sorbus alnifolia (Korean mountain ash)

Common pest name

Cedar-Quince rust; Quince rust; Rust of apple; Rust of juniper; Rust of quince

Scientific pest name

Gymnosporangium clavipes

Type

Fungus

Current status in UK

Absent

Likelihood to spread to UK (1 is very low - 5 is very high)

2

Impact (1 is very low - 5 is very high)

4

General biosecurity comments

EU regulated rust disease which helps mitigate against introduction. A review of EU regulations will help to ensure that all hosts are regulated.

Defra's Risk register #3

Plant name

Sorbus alnifolia (Korean mountain ash)

Common pest name

Lance nematode; Nematode; Lance

Scientific pest name

Hoplolaimus spp.

Type

Nematode

Current status in UK

Absent

Likelihood to spread to UK (1 is very low - 5 is very high)

2

Impact (1 is very low - 5 is very high)

4

General biosecurity comments

Nematode species potentially affecting a wide variety of crops; prohibition of soil likely to mitigate risk substantially; keep under review in light of interceptions or findings should they occur in the EU.

About this section

Our plants are under greater threat than ever before. There is increasing movement of plants and other material traded from an increasing variety of sources. This increases the chances of exotic pests arriving with imported goods and travellers, as well as by natural means. Shoot is working with Defra to help members to do their part in preventing the introduction and spread of invasive risks.

Traveling or importing plants? Please read "Don't risk it" advice here

Suspected outbreak? Click here for contact details to report to the relevant authority.

Date updated: 7^th March 2019 For more information visit: https://planthealthportal.defra.gov.uk/