Sempervivum arachnoideum subsp. tomentosum (C.B. Lehm. & Schnittsp.) Schinz & Thell.

RHS Plant Profile

woolly cobweb houseleek

RHS 2003

Synonyms

Sempervivum arachnoideum 'Laggeri'
Sempervivum webbianum

Alpine Rockery Cactus Succulent

Buy this from Plant Nurseries
8 Suppliers

A mat-forming evergreen perennial with fleshy rosettes to 4cm in width, densely covered with cobwebby white hairs. Starry pink flowers 1.5cm in width are borne in flat cymes on stems to 15cm

Position

Full sun

Soil Types

Loam, Sand

Max Height

Up to 10 cm

Max Spread

0.1-0.5 metres

Size

Time to Maturity: 2–5 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: North–facing or South–facing or East–facing
Exposure: Sheltered
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

H1A: under glass all year (>15C)
H1B: can be grown outside in the summer (10 - 15)
H1C: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20): 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: Alps, Pyrenees

How to Grow

Cultivation

Grow in moderately fertile, humus-rich, moist but well-drained soil in full sun

Propagation

Propagate by offsets

Suggested planting locations and garden types

Coastal
Gravel garden
Patio and container plants
Wildlife gardens
City and courtyard gardens
Cottage and informal garden
Rock garden
Flower borders and beds
Garden edging

Pruning

No pruning required

Pests

May be susceptible to slugs

Diseases

Generally disease-free