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Fraxinus americana (White ash)

Beginner
skill rating
1 hour care
per year
25m
Max height
15m
Max spread
20-50 years
To maturity

Plant details

Botanical name

Fraxinus americana

Other names

White ash, American ash

Genus

Fraxinus Fraxinus

Species

F. americana - F. americana is a vigorous, broadly columnar, deciduous tree with pinnate, dark green leaves divided into five to nine, tapered, oblong, ovate, or lance-shaped leaflets turning yellow or purple in autumn. Clusters of dull purple flowers in spring are followed by pendent, winged fruit.


Fraxinus americana is: Deciduous

Habit

Broadly columnar

Flower

Purple in Spring

Foliage

Dark-green in Spring; Dark-green in Summer; Purple, Yellow in Autumn

How to care

Watch out for

Pests

Generally pest-free

Diseases

Ash dieback.

General care

Pruning

Pruning group 1

Propagation

Tends to self-seed freely in ideal growing conditions. Sow seed in autumn in an open frame. Can be sown in spring after chilling in a refrigerator for 2-3 months.

Propagation methods

Seed, Grafting


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Where to grow

Fraxinus americana (White ash) will reach a height of 25m and a spread of 15m after 20-50 years.

Suggested uses

Low Maintenance, Foliage only, Coastal, Woodland

Cultivation

Grow in fertile, moist but well-drained, neutral to alkaline soil in full sun. Will tolerate a wide range of conditions. Autumn colour often varies considerably from year to year.

Soil type

Chalky, Clay, Loamy, Sandy (will tolerate most soil types)

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Alkaline, Neutral

Light

Full Sun

Aspect

North, South, East, West

Exposure

Exposed, Sheltered

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

Hardy (H4)

Companion plants

Botanical name

Fraxinus americana

Other names

White ash, American ash

Genus

Fraxinus Fraxinus

Species

F. americana - F. americana is a vigorous, broadly columnar, deciduous tree with pinnate, dark green leaves divided into five to nine, tapered, oblong, ovate, or lance-shaped leaflets turning yellow or purple in autumn. Clusters of dull purple flowers in spring are followed by pendent, winged fruit.

Native to

Eastern North America

Foliage

Deciduous

Habit

Broadly columnar


Colour

Flower

Purple in Spring

Foliage

Dark-green in Spring; Dark-green in Summer; Purple, Yellow in Autumn


How to care

Watch out for

Pests

Generally pest-free

Diseases

Ash dieback.

General care

Pruning

Pruning group 1

Propagation

Tends to self-seed freely in ideal growing conditions. Sow seed in autumn in an open frame. Can be sown in spring after chilling in a refrigerator for 2-3 months.

Propagation methods

Seed, Grafting


Monthly care advice


Where to grow

Fraxinus americana (White ash) will reach a height of 25m and a spread of 15m after 20-50 years.

Suggested uses

Low Maintenance, Foliage only, Coastal, Woodland

Cultivation

Grow in fertile, moist but well-drained, neutral to alkaline soil in full sun. Will tolerate a wide range of conditions. Autumn colour often varies considerably from year to year.

Soil type

Chalky, Clay, Loamy, Sandy (will tolerate most soil types)

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Alkaline, Neutral

Light

Full Sun

Aspect

North, 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 9, Zone 8, Zone 7, Zone 6, Zone 5, Zone 4, Zone 3

Defra's Risk register #1

Plant name

Fraxinus americana (White ash)

Common pest name

Alfalfa dwarf; Anaheim disease; California vine disease; Dwarf disease of alfalfa; Dwarf disease of lucerne; Leaf scald of oleander; Leaf scald of plum; Leaf scorch; Phony disease of peach; Pierce's disease of grapevine; Variegated chlorosis of citrus

Scientific pest name

Xylella fastidiosa subsp. multiplex

Type

Bacterium

Current status in UK

Absent

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

3

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

4

General biosecurity comments

A bacterial disease with a wide host range detected in Corsica. Although EU regulated; there remains some concern about the risk of introduction. This subspecies is known to be able to thrive in cooler climates. Should an outbreak occur; there would be a need for eradication action which would result in environmental and social impacts.

Defra's Risk register #2

Plant name

Fraxinus americana (White ash)

Common pest name

Ash yellows

Scientific pest name

Candidatus Phytoplasma fraxini

Type

Phytoplasma

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

Pathogen causing phytoplasma disease of certain tree species in the Americas. EU regulation already provides some mitigation against the risk of introduction; but could be further strengthened.

Defra's Risk register #3

Plant name

Fraxinus americana (White ash)

Common pest name

Japanese swift moth

Scientific pest name

Endoclita excrescens

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)

4

General biosecurity comments

Polyphagous moth pest whose larvae feed off a range of herbaceous and woody hosts. Native to East Asia where substantial impacts have been observed; and current import requirements do not fully mitigate the risk of introduction. A PRA will help to assess the level of risk more fully.

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

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This plant likes... Garden match
Soil types: Chalky, Clay, Loamy, Sandy (will tolerate most soil types) Tell us...
Soil drainage: Moist but well-drained, Well-drained Tell us...
Soil pH: Alkaline, Neutral Tell us...
Light: Full Sun Tell us...
Aspect: North, South, East, West Tell us...
Exposure: Exposed, Sheltered Tell us...
Hardiness: Hardy (H4) Tell us...

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