Salix helvetica (Swiss willow)

Botanical name

Salix helvetica

Other names

Swiss willow, Swiss silver willow

Genus

Salix Salix

Species

helvetica - S. helvetica is a dwarf, many-branched deciduous shrub with a compact, rounded habit and grey-green lance-shaped leaves which have downy undersides. In early spring, silver-grey catkins open from golden buds.

Foliage

Deciduous

Tree shape

Rounded, Upright

Awards

RHS AGM (Award of Garden Merit)

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Colour

Flower

Silvery-grey in Spring

Foliage

Grey-green in Spring; Grey-green in Summer

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How to care

Watch out for

Specific pests

Aphids , Caterpillars , Leaf beetles (willow and poplar) , Sawflies

Specific diseases

Anthracnose diseases , Canker , Rust

General care

Pruning

Benefits from a little light pruning after flowering in early spring.

Propagation methods

Hardwood cuttings, Seed, Softwood cuttings

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Monthly care advice

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Where to grow

Salix helvetica (Swiss willow) will reach a height of 0.6m and a spread of 0.4m after 20-50 Years.

Suggested uses

Low Maintenance, Waterside

Cultivation

Plant in moisture-retentive soil in a sunny position.

Soil type

Clay, Loamy, Sandy

Soil drainage

Boggy damp conditions, Moist but well-drained, Moisture-retentive

Soil pH

Acid, 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 10, Zone 9, Zone 8, Zone 7, Zone 6, Zone 5, Zone 4, Zone 3, Zone 2

Defra's Risk register #1

Plant name

Salix helvetica (Swiss willow)

Common pest name

Scientific pest name

Agrilus fleischeri

Type

Insect

Current status in UK

Absent

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

4

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

5

General biosecurity comments

Pest of poplar; native to East Asia. Likely to be damaging if introduced to the UK. Protecting against the risk of entry via wood packaging material and other means remains a priority. A Europe-wide assessment would be helpful; to consider strengthened regulation.

Defra's Risk register #2

Plant name

Salix helvetica (Swiss willow)

Common pest name

Namangan longhorn beetle

Scientific pest name

Xylotrechus namanganensis

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 pest originating in Asia; some uncertainty regarding risk to UK; further work needed to assess climatic suitability.

Defra's Risk register #3

Plant name

Salix helvetica (Swiss willow)

Common pest name

watermark disease of willow; willow vascular wilt; willow watermark disease; willow wilt

Scientific pest name

Brenneria salicis

Type

Bacterium

Current status in UK

Present (Limited)

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

2

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

4

General biosecurity comments

Bacterial organism causing watermark disease; which affects willow used for cricket bat production. Established in parts of England; despite long-standing powers for local authorities to take action; which have now been revoked.

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/