Sempervivum arachnoideum subsp. tomentosum

Scientific Name

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

Common Names

Woolly Cobweb Houseleek, Cobweb Hen and Chicks


Sempervivum tomentosum, Sempervivum laggeri, Sempervivum arachnoideum var. laggeri, Sempervivum webbianum

Scientific Classification

Family: Crassulaceae
Subfamily: Sedoideae
Tribe: Sedeae
Subtribe: Sedinae
Genus: Sempervivum


Sempervivum arachnoideum subsp. tomentosum is a mat-forming succulent that forms rosettes of fleshy, obovate, mid-green to red leaves, densely covered in white, cobweb-like hairs. The rosettes grow up to 1.6 inches (4 cm) in diameter. Flowers are pink, star-shaped, up to 0.6 inches (1.5 cm) in diameter, and borne in flat cymes on stems up to 6 inches (15 cm) tall.


USDA hardiness zone 4a to 10b: from −30 °F (−34.4 °C) to 40 °F (+4.4 °C).

How to Grow and Care

Because of the variability of Cobweb Houseleek, they easily adapt to the local conditions, and due to the small gene pool, they become a form or variety quite quickly, perfectly adapted to the local conditions of heat and cold as well as the amount of snow or rain and at which times of the year.

Relatively easy to grow in a container or a rock garden, scree bed, wall crevice, trough, or alpine house. They are ideal in so many ways, as they quickly start to form very tight clusters of rosettes, filling in Sempervivum walls, mosaics, and topiary, and their shallow yet fibrous root systems hold soil in place even in vertical plantings. After the plant blooms and sets seed, it will die, but many offsets will take its place.

Plant in well-drained succulent soil mix in full sun to light shade. Water regularly during the growing season and allow the soil to dry out before watering again. Water very little during the winter months. See more at How to Grow and Care for Cobweb Houseleek (Sempervivum arachnoideum).


Native to the mountains of central and southern Europe.


  • Back to genus Sempervivum
  • Succulentopedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus

Photo Gallery

Subscribe now and be up to date with our latest news and updates.


Sempervivum arachnoideum ssp. tomentosum: This S. arachnoideum is very heavily cobwebbed with 3/4" plants. It gets many tiny chicks on short stolons. They make nice neat clumps and have a slight rosy cast. Can flush lightly purple in spring.

After trials by the Royal Horticultural Society, S. arachnoideum tomentosum earned the Award of Garden Merit in 1993 and was reconfirmed in 2008.

Hens & Chicks need plenty of outdoor sunlight to show their best colors and maintain a tight rosette form. They thrive in gritty, well-draining soils and pots with drainage holes. They produce new offsets or "chicks" on stolons. These chicks can be lefts to form tidy clusters or removed to share and transplant.

Sempervivum do most of their growing in the spring and summer, and will thrive with weekly watering and afternoon shade if temperatures exceed 85F. They are incredibly frost hardy and will happily overwinter under a blanket of snow. Protect from heavy rains and standing water to prevent rot.

Sempervivum arachnoideum subsp. tomentosum – Succulent plants

Sempervivum arachnoideum subsp. tomentosum is an ornamental mat-forming, evergreen perennial succulent with rosettes up to 4 cm in diameter, of fleshy, obovate, mid-green to red leaves, densely covered in white, cobweb-like hairs. The star-shaped, pink flowers up to 1.5 cm in diameter are borne in flat cymes on stems up to 15 cm tall.

Scientific Classification:

Family: Crassulaceae
Subfamily: Sedoideae
Tribe: Sedeae
Subtribe: Sedinae
Genus: Sempervivum

Scientific Name: Sempervivum arachnoideum subsp. tomentosum (C.B.Lehm. & Schnittsp.) Schinz & Thell.
Synonyms: Sempervivum tomentosum, Sempervivum laggeri, Sempervivum arachnoideum var. laggeri, Sempervivum webbianum.
Common Names: Woolly Cobweb Houseleek, Cobweb Hen and Chicks.

How to grow and maintain Sempervivum arachnoideum subsp. tomentosum:

It thrives best in full sun to light shade. In indoor, an east or west-facing window where they receive four to six hours of sunlight is ideal.

It needs excellent drainage. Poor, sandy soil would be just fine. You could work some peat into heavier soil, to lighten them and improve drainage.

Water regularly during the summer and spring. keep the soil evenly moist but not soggy. You can allow the topsoil to become slightly dry between each watering. Reduce water in the winter.

It prefers an average summer temperature 65 degrees Fahrenheit – 70 degrees Fahrenheit / 18 degrees Celsius – 21 degrees Celsius. In winter, some varieties can withstand temperatures down to freezing.

Fertilize with a controlled-release fertilizer at the beginning of the season or weekly with a weak liquid solution. Use a balanced 20-20-20 fertilizer at 1/4 strength on mature plants, and a fertilizer with less nitrogen on young plants.

Re-pot as needed, preferably during the warm season. To re-pot, a succulent, make sure the soil is dry before repotting, then gently remove the pot. Knock away the old soil from the roots, making sure to remove any rotted or dead roots in the process. Treat any cuts with a fungicide. Place the plant in its new pot and backfill with potting soil, spreading the roots out as you re-pot. Leave the plant dry for a week or so, then begin to water lightly to reduce the risk of root rot.

Pests and Diseases:
It has no serious pest or disease problems. Cobweb Houseleek can get vine weevil and may be subject to rust.


It can be easily propagated by seed sown in spring or root offsets in spring. Sempervivum earned their famous name “Hen and Chicks” from their growth habit. The mother plant, or hen, sends off numerous offsets, which will cluster around her base like chicks. These offsets can be easily re-potted, or the plants can be left to form a clumping mat.

Plants→Sempervivum→Hen and Chicks (Sempervivum arachnoideum subsp. tomentosum (laggeri) )

Botanical names:
Sempervivum arachnoideum subsp. tomentosum (laggeri)Accepted
Sempervivum laggeriSynonym

Data specific to Sempervivum (Edit)
Other Details: Form of arachnoideum subsp tomentosum named after the botanist Lagger.
History of species or Cultivar: S. laggeri Schott ex Hallier (1892) / S. arachnoideum ssp. tomentosum (C. B.Lehmann & Schnittspahn) Schinz & Thellung
Awards: AGM: 1993
Soil type: Dry
Well draining
Loamy / Medium
Sandy / light
Other: The soil type will depend on what your weather conditions are like. Just make sure it drains well.
Water: Very low
Does not like wet feet
Uses: Accent
Pests and Diseases: Pest resistant

General Plant Information (Edit)
Plant Habit: Cactus/Succulent
Life cycle: Perennial
Sun Requirements: Full Sun to Partial Shade
Minimum cold hardiness: Zone 4a -34.4 °C (-30 °F) to -31.7 °C (-25 °F)
Leaves: Evergreen
Flowers: Showy
Flower Time: Summer
Late summer or early fall
Other: It may be several years before it blooms
Uses: Provides winter interest
Wildlife Attractant: Bees
Resistances: Deer Resistant
Propagation: Seeds: Provide light
Stratify seeds: Stratifying seeds may improve germination, but is not required
Suitable for wintersowing
Sow in situ
Will not come true from seed
Propagation: Other methods: Offsets
Containers: Suitable in 1 gallon
Suitable in 3 gallon or larger
Needs excellent drainage in pots
Miscellaneous: Monocarpic

Also called:
Sempervivum arachnoideum L. subsp. tomentosum
Sempervivum laggerii

Thread Title Last Reply Replies
Sempervivum Chat & photos 2018 by CDsSister Apr 10, 2019 5:14 PM 3,385
Database question by growitall May 14, 2014 7:53 PM 18

» Search the Sempervivum Database: by characteristics or by cultivar name

Times are presented in US Central Standard Time

Today's site banner is by dirtdorphins and is called "muscari"

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Watch the video: Sempervivum arachnoideum medicinal plant

Previous Article

What is good about the melon - the beneficial properties of the sun fruit on guard of health and a slim figure

Next Article