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Herbaceous Perennial

Mertensia maritima

oysterplant

M. maritima is a spreading, prostrate perennial with fleshy, blue-grey-green leaves, up to 10cm long, and branched clusters of bright blue, bell-shaped flowers opening from pink buds in early summer

Other common names
gromwell
oysterleaf
see moresea bugloss
sea lungwort
Synonyms
Mertensia maritima subsp. asiatica
Mertensia asiatica
see moreStenhammaria maritima
Mertensia simplicissima
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Size
Ultimate height
Up to 10cm
Time to ultimate height
2–5 years
Ultimate spread
0.1–0.5 metres
Growing conditions
Sand
Moisture
Well–drained
pH
Acid, Alkaline, Neutral
Colour & scent
StemFlowerFoliageFruit
Spring Blue Green Grey Silver
Summer Blue Pink Blue Green Grey Silver
Autumn Blue Green Grey Silver
Winter
Position
  • Full sun
  • Partial shade
Aspect

West–facing or East–facing

Exposure
Sheltered
Drought resistance
Yes
Hardiness
H5
Botanical details
Family
Boraginaceae
Native to the UK
No
Foliage
Deciduous
Habit
Trailing
Genus

Mertensia are herbaceous perennials with usually grey-green or blue-green leaves and nodding, blue, tubular or narrowly bell-shaped flowers

Name status

Correct

Plant range
Northern Hemisphere

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How to grow

Cultivation

Grow in sharply-drained, gritty soil with low fertility in full sun with some midday shade

Propagation

Propagate by seed sown in containers in a cold frame in autumn; keep young plants shaded and do not allow the soil to dry out. Divide plants carefully as new growth begins in spring

Suggested planting locations and garden types
  • Coastal
  • Cottage and informal garden
  • Gravel garden
  • Patio and container plants
Pruning

Cut back after flowering

Pests

May be attacked by slugs and snails

Diseases

Generally disease free

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