Marrubium supinum (Scallop shell horehound)

Botanical name

Marrubium supinum

Other names

Scallop shell horehound, Scallop shell, Spanish horehound

Genus

Marrubium Marrubium

Species

M. supinum - M. supinum is a mound- or mat-forming, evergreen with rounded, scalloped, velvety, grey-green leaves and erect stems bearing whorls of tubular, lavender or lilac-pink flowers in summer.

Native to

Northern Africa, Southern Europe

Foliage

Evergreen

Habit

Cushion or Mound Forming, Mat Forming

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Colour

Flower

Lavender in Summer

Foliage

Grey-green in All seasons

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How to care

Watch out for

Specific pests

Leafhoppers

General care

Pruning

Cut back after flowering.

Propagation

Sow seed in a cold frame in spring or autumn. Germination tends to be erratic and slow.

Propagation methods

Division, Basal cuttings, Seed

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Monthly care advice

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Where to grow

Marrubium supinum (Scallop shell horehound) will reach a height of 0.3m and a spread of 0.6m after 2-5 years.

Suggested uses

Beds and borders, City, Containers, Desert garden/Xeriscaping, Drought Tolerant, Foliage only, Gravel, Ground Cover, Rock

Cultivation

Best in poor, dry, well-drained, preferably neutral soil in sun.

Soil type

Chalky, Loamy, Sandy

Soil drainage

Well-drained

Soil pH

Acid, Alkaline, Neutral

Light

Full Sun

Aspect

South, 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

Defra's Risk register #1

Plant name

Marrubium supinum (Scallop shell horehound)

Common pest name

Golden twin spot; Green garden looper; Groundnut semilooper; Tomato looper

Scientific pest name

Chrysodeixis chalcites

Type

Insect

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)

3

General biosecurity comments

Migrant moth that poses a threat to protected cultivation Raising awareness of industry to respond to incidents & prevent transfer from imported produce should reduce risks further.

Defra's Risk register #2

Plant name

Marrubium supinum (Scallop shell horehound)

Common pest name

tomato thrips

Scientific pest name

Ceratothripoides brunneus

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

Thrips present in Africa; the Caribbean and parts of Asia; frequently intercepted in the UK. Can cause significant damage to tomatoes and other crops in countries where it is present. Europe wide PRA will consider its potential to establish and cause damage.

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/