Sempervivum arachnoideum

RHS Plant Profile
cobweb houseleek

Other common names

cobweb sedum

Award of Garden Merit
Alpine Rockery Cactus Succulent

An evergreen perennial forming a mat of fleshy rosettes 1-3cm across, leaves green or reddish, with cobwebby white hairs at the tips. Starry pink flowers 1cm in width in flat cymes on stems to 12cm

Position

Full sun

Soil Types

Loam, Sand

Max Height

Up to 10 cm

Max Spread

0.1-0.5 metres

Size

Time to Maturity
5–10 years
Max Spread
0.1-0.5 metres
Max Height
Up to 10 cm

Growing Conditions

Loam Sand
Moisture
Well–drained
pH
Acid or Alkaline or Neutral

Position

Full sun
Aspect
South–facing or North–facing or West–facing or East–facing
Exposure
Exposed or Sheltered
Hardiness
H7

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Crassulaceae
Native to GB/Ireland
No
Foliage
Evergreen
Habit
Matforming
Genus
Sempervivum are evergreen perennials forming mats of fleshy-leaved rosettes, often attractively coloured, with star-shaped pink or pale yellow flowers in summer
Name Status
Correct
Plant Range
Pyrenees to Carpath.

How to Grow

Cultivation

Grow in moderately fertile well-drained soil in full sun. Protect from excessive winter wet. Suitable for rock garden, scree bed, wall crevice, trough or alpine house

Propagation

Propagate by seed sown in spring, or root offsets in spring

Suggested planting locations and garden types

  • Cottage and informal garden
  • Gravel garden
  • Patio and container plants
  • Rock garden
  • Flower borders and beds
  • Garden edging
  • Ground cover

Pruning

No pruning required

Pests

May be susceptible to vine weevil

Diseases

May be susceptible to a rust