Rhododendron ponticum (Pontic rhododendron)

Botanical name

Rhododendron ponticum

Other names

Pontic rhododendron

Genus

Rhododendron Rhododendron

Species

R. ponticum - R. ponticum is a vigorous evergreen shrub, with glossy, dark-green leaves and clusters of funnel-shaped red purple or sometimes white flowers, sometimes spotted yellow green on the inside, in summer. May become invasive.

Foliage

Evergreen

Habit

Rounded, Bushy

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Colour

Flower

Reddish-purple, White in Summer

Foliage

Dark-green in All seasons

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How to care

Watch out for

Specific pests

Aphids , Caterpillars , Leafhoppers , Vine weevil

Specific diseases

Powdery mildew , Rhododendron bud blast , Rhododendron petal blight , Silver leaf

General care

Propagation methods

Semi-hardwood cuttings, Grafting, Layering

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Monthly care advice

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Where to grow

Rhododendron ponticum (Pontic rhododendron) will reach a height of 8m and a spread of 6m after 10-20 years.

Suggested uses

Banks and Slopes, Cottage/Informal, Beds and borders, Wallside and trellises, Containers

Cultivation

Plant in moist, humus-rich, free-draining, acid soil in sun or dappled shade. Plant shallowly. Protect from frost to prevent damage to flowers.

Soil type

Clay, Loamy, Sandy

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Acid

Light

Partial Shade, Full Sun

Aspect

North, South, East, West

Exposure

Sheltered

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

Hardy (H4)

USDA zones

Zone 8, Zone 7, Zone 6

Defra's Risk register #1

Plant name

Rhododendron ponticum (Pontic rhododendron)

Common pest name

Ramorum leaf blight; Ramorum shoot dieback; Rhododendron twig blight; Sudden oak death

Scientific pest name

Phytophthora ramorum

Type

Oomycete

Current status in UK

Present (Limited)

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

4

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

4

General biosecurity comments

Pathogen of larch and other hosts subject to EU emergency legislation. A containment strategy is in place in the UK; reflecting its presence in wider environment/forestry settings in some areas. EU regulatory status is under review.

Defra's Risk register #2

Plant name

Rhododendron ponticum (Pontic rhododendron)

Common pest name

leaf rust of blueberry

Scientific pest name

Thekopsora minima

Type

Fungus

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)

3

General biosecurity comments

Rust fungus affecting blueberry and hemlock. This fungus has been detected in Europe (Germany; Netherlands and Portugal). Some uncertainty about the suitability of UK native host species. But the case for regulation should be considered based on the EPPO PRA.

Defra's Risk register #3

Plant name

Rhododendron ponticum (Pontic rhododendron)

Common pest name

Elm spanworm; Ennomid; white; Linden moth; snow-white

Scientific pest name

Ennomos subsignaria

Type

Insect

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)

3

General biosecurity comments

Polyphagous moth pest which defoliates deciduous trees and; with repeated infestation; can cause tree death. Present in North America 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: 7^th March 2019 For more information visit: https://planthealthportal.defra.gov.uk/