Cobweb houseleek Sempervivum arachnoideum
ABOUT
The cobweb houseleek is an eye-catching succulent known for its unique appearance resembling a dense rosette of fleshy, spatula-shaped leaves. These leaves are typically green, sometimes with a hint of red at the tips, giving the plant a vibrant, two-toned effect. What distinguishes the cobweb houseleek from other succulents is its intricate cobweb-like structures, which are formed by fine, white, hair-like filaments crisscrossing over the top of the rosettes. This webbing gives the plant a distinctive, woolly look as if it's been covered by a spider's silk. The plant usually forms clumps by producing offsets, and these clusters intensify its lush, textured appearance, making it a popular choice for rock gardens, green roofs, and as groundcover in dry, sunny areas. During its blooming season, the cobweb houseleek sends up flowering stems bearing star-shaped flowers that add a further dimension of beauty to the plant. The flowers are usually a vibrant shade, standing out against the green and webbed backdrop of the leaves.
About this plant
NamesFamily
Crassulaceae
Synonyms
Cobweb Houseleek, Spider Web Hens and Chicks, Cobweb Sedum, Cobweb Hen and Chick
Common names
Sempervivum alpinum Griseb. & Schenk, Sempervivum arachnoideum var. bryoides (Haw.) G.Don, Sempervivum arachnoideum var. tomentosum C.B.Lehm., Sempervivum bryoides Haw., Sempervivum tomentosum Lam.
ToxicityTo humans
Cobweb houseleek (Sempervivum arachnoideum) is not considered toxic to humans. This means that ingestion of parts of the plant typically does not lead to poisoning or produce harmful effects.
To pets
Cobweb houseleek is generally considered non-toxic to pets as well. It is unlikely to cause poisoning if a pet were to ingest parts of the plant. There should be no significant consequences from the ingestion of this plant by pets.
CharacteristicsLife cycle
Perennials
Foliage type
Evergreen
Color of leaves
Green
Flower color
Pink
Height
0.25 feet (0.08 meters)
Spread
0.5 feet (0.15 meters)
Plant type
Succulent
Hardiness zones
5
Native area
Europe
Benefits
General Benefits- Low Maintenance: Sempervivum arachnoideum, commonly known as cobweb houseleek, is a hardy plant that requires minimal care, making it ideal for beginner gardeners.
- Drought Tolerant: Cobweb houseleek is highly resistant to drought, which allows it to thrive in dry conditions where other plants might struggle.
- Cold Hardy: This plant can survive in cold temperatures and is frost resistant, suitable for growing in a variety of climates.
- Ground Cover: Cobweb houseleek plants can spread across the ground, helping to prevent soil erosion and suppress weeds in the garden.
- Rooftop Gardening: The ability to tolerate extreme conditions makes cobweb houseleeks ideal for rooftop gardens and rockeries.
- Aesthetic Appeal: With its unique rosettes and web-like structures, cobweb houseleek adds visual interest and texture to gardens and containers.
- Propagation Ease: Cobweb houseleek can easily be propagated from offsets, allowing gardeners to expand their collection or share with others.
- Insect Resistance: The thick foliage and sap of cobweb houseleeks make them less appealing to many common garden pests.
Medical Properties- Astringent: Sempervivum arachnoideum, commonly known as Cobweb Houseleek, has been used for its astringent properties, which help to tighten and tone tissues.
- Anti-inflammatory: The plant has been traditionally used to help reduce inflammation when applied topically to the skin.
- Antiseptic: Cobweb Houseleek possesses antiseptic properties, which can help to prevent infection in minor skin wounds.
- Vulnerary: It is known for its wound-healing abilities and has been used as a home remedy to promote the healing of cuts and abrasions.
Air-purifying QualitiesThis plant is not specifically known for air purifying qualities.
Other Uses- "Cobweb houseleek" can be used as a protective charm in folklore; people believed that planting it on roofs or near the entrance of homes would ward off lightning and fire.
- Cobweb houseleek can also be utilized as a natural dye source; the leaves can produce subtle colors on fabrics and yarns when treated correctly.
- The succulent nature of cobweb houseleek allows it to be a component in green roof installations, serving as insulation and contributing to urban biodiversity.
- When planted in garden borders, cobweb houseleek can act as a living mulch, helping to control weeds and retain soil moisture.
- This plant's unique web-like appearance makes it an attractive choice for fairy gardens and miniature landscaping.
- Cobweb houseleek's hardiness and tolerance for poor soil make it a valuable ground cover in rock gardens and xeriscaping designs to combat soil erosion.
- With careful arrangement, cobweb houseleeks can be grown as 'living walls' to create vertical green spaces in urban environments.
- Cobweb houseleek leaves can be used as stamps for botanical prints in art projects or natural crafts due to their unique textures and shapes.
- These succulents can be part of living wreaths or holiday decorations, providing a touch of greenery that requires minimal upkeep.
- Cobweb houseleek can act as a companion plant in vegetable gardens, potentially deterring pests with its thick mat of foliage and dense webbing.
Interesting Facts
Feng ShuiThe Sempervivum arachnoideum, more commonly known as the Cobweb Houseleek, is not used in Feng Shui practice.
Zodiac Sign CompitabilityThe Cobweb Houseleek is not used in astrology practice.
Plant Symbolism- Resilience and Survival: Also known as the 'Cobweb Houseleek,' Sempervivum arachnoideum symbolizes enduring love and tenacity in the face of hardship, due to its ability to withstand poor soil and drought conditions.
- Protection: Historically placed on rooftops to ward off lightning and fire, Cobweb Houseleek represents safety and a shield against adversity.
- Renewal and Rebirth: Cobweb Houseleeks are known for their regenerative properties, where they die back and regrow, symbolizing regeneration and the cycle of life.
- Timelessness: Their perennial nature and evergreen characteristics represent eternal life and enduring principles or relationships.
WaterThe Cobweb Houseleek should be watered sparingly, as it is a succulent that thrives with minimal moisture. Allow the soil to dry out completely between waterings, then water thoroughly. As a general rule of thumb, provide about 0.25 gallons of water every two weeks during the active growing season in spring and summer. Reduce watering to once a month or less during the dormant season in fall and winter, depending on the humidity of your environment.
LightCobweb Houseleek does best in full sun to partial shade. The ideal spot for this plant is a location where it receives at least four to six hours of sunlight a day. Be cautious of too much intense afternoon sun in hotter climates, which can scorch the leaves. The plant can tolerate some light shade, especially in the hottest parts of the day.
TemperatureThe Cobweb Houseleek prefers temperate conditions and will thrive in temperatures ranging from 65°F to 75°F. It can withstand minimum temperatures down to about 20°F but should be protected from prolonged freezing conditions. The plant can tolerate a wide range of temperatures as long as they are not extreme, but always aim to provide a stable environment with minimal temperature fluctuations.
PruningPruning the Cobweb Houseleek is usually not necessary as it is a low-maintenance plant. However, removing dead or withered leaves will encourage healthy growth and reduce the risk of disease. Prune damaged leaves at the base as needed, preferably during the growing season, to maintain a compact and attractive shape. There is no need for regular pruning; simply tidy up the plant to keep it looking its best.
CleaningAs needed
SoilThe best soil mix for Cobweb Houseleek is well-draining and gritty, with a mix of potting soil, coarse sand, and perlite or pumice. It prefers a slightly acidic to neutral pH, ranging from 6.0 to 7.5.
RepottingCobweb Houseleek should be repotted every 2-3 years to provide fresh soil and to accommodate growth, though it can often thrive even without frequent repotting.
Humidity & MistingCobweb Houseleek prefers low humidity environments typical of its native alpine habitats and can suffer in high humidity conditions.
Suitable locationsIndoor
Place in bright light, well-draining soil, water sparingly.
Outdoor
Full sun to partial shade, well-draining soil, hardy.
Hardiness zone
3-8 USDA
Life cycleCommonly known as the Cobweb Houseleek, Sempervivum arachnoideum begins its life cycle when seeds germinate in spring or summer, requiring well-draining soil and plenty of sunlight. Seedlings establish a central rosette composed of fleshy leaves, which over time can produce offsets (pups) at the base, facilitating asexual reproduction. These rosettes mature after one year, becoming dense and often developing cobweb-like structures across the leaves. The plant may live several years without flowering, focusing energy on vegetative growth and clonal propagation. When conditions are favorable, usually in the plant's third or fourth year, it will produce a flowering stalk during the summer, which can reach up to 12 inches tall and bears star-shaped, pinkish flowers. After flowering, which is the culmination of its life cycle, the main rosette usually dies, but the plant ensures its survival by the numerous offsets it has produced that will continue to grow and eventually repeat the life cycle.
PropogationPropogation time
Spring to Summer
Sempervivum arachnoideum, commonly known as Cobweb Houseleek, is best propagated by offsets. In late spring to early summer, the plant produces small rosette offsets around its base. These offsets are easily removed by gently twisting them off the parent plant, ensuring that there is a portion of the stem attached. The offsets can be placed in a well-draining soil mixture and kept slightly moist until they establish roots, which usually takes a few weeks. It is important to provide the offsets with bright, indirect sunlight and to avoid overwatering during this period. Once rooted, they can be transplanted into their final location, where they will grow into mature rosettes. This method of vegetative propagation is simple and highly effective for expanding your collection of Cobweb Houseleek.
