Betula nigra (River birch)

Botanical name

Betula nigra

Other names

River birch, Black birch, Red birch

Genus

Betula Betula

Species

B. nigra - B. nigra is a conical to spreading, deciduous tree with peeling, reddish-brown bark, glossy, diamond-shaped, mid- to dark green leaves turning yellow in autumn, and yellow-brown, male flower catkins in early spring.

Native to

Eastern United States

Foliage

Deciduous

Habit

Broadly conical, Spreading

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Colour

Flower

Yellow-brown in Spring

Foliage

Mid-green in Spring; Mid-green in Summer; Yellow in Autumn

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How to care

Watch out for

Specific pests

Aphids , Leaf-mining sawflies , Sawflies

Specific diseases

Honey fungus , Leaf spot , Birch rust

General care

Pruning

Pruning group 1.

Propagation methods

Grafting, Softwood cuttings, Seed

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Monthly care advice

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Where to grow

Betula nigra (River birch) will reach a height of 18m and a spread of 12m after 20-50 years.

Suggested uses

Architectural, Foliage only, Woodland

Cultivation

Grows well in a wide range of soils and situations.

Soil type

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

Soil drainage

Moist but well-drained, Moisture-retentive, Well-drained

Soil pH

Acid, Alkaline, Neutral

Light

Partial Shade, 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

Defra's Risk register #1

Plant name

Betula nigra (River birch)

Common pest name

Bronze birch borer

Scientific pest name

Agrilus anxius

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

Recognised as a significant threat to birch but EU regulation should help to mitigate the threat.

Defra's Risk register #2

Plant name

Betula nigra (River birch)

Common pest name

Japanese long scale; Japanese maple scale; Long scale; Japanese; Pear white scale

Scientific pest name

Lopholeucaspis japonica

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

Regulated only on Citrus at present; regulation on other hosts needs to be considered. Only likely to be a pest under glass in UK.

Defra's Risk register #3

Plant name

Betula nigra (River birch)

Common pest name

Asian longhorn beetle; Starry sky beetle

Scientific pest name

Anoplophora glabripennis

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

Recognised threat to a wide range of deciduous tress native to the UK. Already regulated it is a priority for continued surveillance and statutory action. The risk of entry is further mitigated by EU legislation requiring the monitoring of wooden packaging material originating from China.

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/