Cobweb Houseleek Sempervivum arachnoideum L. subsp. tomentosum (C.b. Lehm. & Schnittsp.) Schinz & Thell.
ABOUT
The plant commonly known as Cobweb Houseleek is a unique and eye-catching succulent. This plant is characterized by its rosettes of tightly packed, fleshy leaves. Each leaf is typically green with a hint of red on the tips, giving it a colorful and attractive appearance. What truly sets this plant apart, though, is the cobwebby structure that seems to weave over the rosettes. This intricate white webbing looks like a network of fine silk threads, stretching from leaf to leaf within each rosette. It's as if the plant has been delicately spun by spiders, with the webbing adding a layer of protection and creating an unusual, almost whimsical visual effect. Because the leaves are so closely knit and covered by the cobweb-like filaments, they give the impression of a cushion or mound. The Cobweb Houseleek has a symmetrically rounded shape, with each rosette looking almost like a flower from a distance due to its dense and neatly packed layers of leaves. When in bloom, it will produce star-shaped flowers on top of slender, leafless stems that emerge from the center of the rosettes. The flowers often contrast beautifully with the foliage, providing a pop of color against the green and white backdrop of the leaves. Overall, the appearance of Cobweb Houseleek is striking, with its blend of colors and unusual cobwebbed surface, making it a popular choice for rock gardens, succulent collections, and as a decorative ground cover that adds an element of intrigue and fascination.
About this plant
NamesFamily
Crassulaceae
Synonyms
Cobweb Houseleek, Spider Web Hens And Chicks
Common names
Sempervivum tomentosum C.B.Lehm. & Schnittsp., Sempervivum arachnoideum var. tomentosum (C.B.Lehm. & Schnittsp.) Hayek.
ToxicityTo humans
The Sempervivum arachnoideum, commonly known as the Cobweb Houseleek, is not known to be toxic to humans. It does not contain any known poisonous compounds, and there are generally no adverse effects from handling or ingesting this plant. However, as with any non-food plant, ingestion is not recommended, and individuals with sensitive skin may possibly experience irritation from handling the plant.
To pets
The Cobweb Houseleek is also not toxic to pets. It is considered safe around both cats and dogs, as it does not contain any substances known to cause poisoning in animals. Consequently, there are no specific symptoms of poisoning associated with this plant because it is not considered poisonous. However, ingestion of non-food items, including plants, can sometimes cause gastrointestinal upset in pets, so it is always prudent to monitor your pets around plants and discourage them from eating non-food vegetation.
CharacteristicsLife cycle
Perennials
Foliage type
Evergreen
Color of leaves
Green
Flower color
Pink
Height
0.5 feet (15 cm)
Spread
1 foot (30 cm)
Plant type
Succulent
Hardiness zones
3
Native area
Europe
Benefits
General Benefits- Decorative Appeal: Sempervivum arachnoideum, commonly known as the Cobweb Houseleek, has a unique appearance with web-like structures, adding an interesting aesthetic to rock gardens and succulent collections.
- Drought Tolerance: As a succulent, it is highly adapted to dry conditions and requires minimal watering, which is beneficial for water conservation in gardening practices.
- Easy Propagation: This plant readily produces offsets, making it easy to propagate and expand your garden without the need for purchasing more plants.
- Cold Hardy: The Cobweb Houseleek can withstand below-freezing temperatures, which makes it suitable for gardens in colder climates where other succulents might not survive.
- Low Maintenance: It requires minimal care, as it is not demanding in terms of soil quality and can thrive with just occasional watering and minimal feeding.
- Ground Cover: Its growth habit can help cover the ground in garden beds, reducing weed growth and soil erosion.
- Roof Gardens: Historically, it was used on rooftops to help insulate and protect the roofs from the elements, illustrating its hardiness and adaptability.
- Pollinator Friendly: During flowering, it attracts bees and other pollinators, which is beneficial for the health of the surrounding flora and the wider ecosystem.
Medical Properties- Anti-inflammatory: Sempervivum arachnoideum, commonly known as Cobweb Houseleek, has been traditionally used for its anti-inflammatory properties.
- Antiseptic: The plant has been used for its antiseptic effects to clean wounds and prevent infection.
- Astringent: It has astringent properties that can help in tightening the skin and reducing irritation.
- Healing agent: Cobweb Houseleek has been applied topically to assist in the healing of minor cuts, burns, and skin irritations.
Air-purifying QualitiesThis plant is not specifically known for air purifying qualities.
Other Uses- Cobweb houseleek can act as a natural insulation layer when grown on green roofs, because of their ability to resist extreme weather conditions and store water.
- They are used in rock gardens to provide an interesting aesthetic due to their unique cobweb-covered rosettes.
- The plant is sometimes used in outdoor model settings or fairy gardens to create miniature landscapes due to its small, intricate appearance.
- Cobweb houseleek can be placed in between paving stones where they can tolerate the compacted soil and enhance the visual appeal of walkways.
- Some use the leaves of the cobweb houseleek to make a natural dye for fabrics, although this is not a widely known practice.
- The succulent is often used in living wall designs, contributing to vertical garden diversity and requiring minimal upkeep.
- They serve as companion plants in the garden that may deter deer and rabbits due to their thick, fleshy leaves which these animals typically avoid.
- In areas prone to wildfires, planting cobweb houseleek can be part of a fire-resistant landscaping strategy due to its high moisture content.
- Decorative arrangements for weddings or events sometimes incorporate cobweb houseleek for its unique appearance and longevity.
- Artists and photographers may use cobweb houseleek as a subject or object in their work to add natural beauty and texture.
Interesting Facts
Feng ShuiThe Hen and Chicks plant is not used in Feng Shui practice.
Zodiac Sign CompitabilityThe Hen and Chicks plant is not used in astrology practice.
Plant Symbolism- Resilience and Perseverance: Sempervivum arachnoideum, commonly known as the Cobweb Houseleek, symbolizes resilience due to its ability to thrive in harsh, rocky environments and regrow even after being uprooted.
- Protection and Safety: Historically, it has been planted on rooftops to protect against lightning and fire, representing a shield against external threats.
- Enduring Love: The plant's perennial nature and the way it produces offsets to reproduce symbolize enduring and ever-growing love.
- Self-sufficiency: Given its minimal water requirements and independent growth, the Cobweb Houseleek represents autonomy and the ability to take care of oneself.
WaterThe plant, commonly known as Cobweb Houseleek, requires moderate watering. During the growing season in spring and summer, water it once a week with approximately 2 ounces of water per plant, ensuring the soil is allowed to dry out between watering sessions. In fall and winter, reduce watering to once every three weeks as the plant goes dormant. Avoid letting water sit in the rosettes to prevent rot.
LightCobweb Houseleek thrives in full sun to light shade. It benefits from at least six hours of direct sunlight daily and can also tolerate partial shade. An ideal spot would be a south-facing window or a sunny spot in an outdoor rock garden where it can receive ample sunlight while being protected from the harsh midday sun.
TemperatureCobweb Houseleek is hardy and can withstand a temperature range from 30°F to 80°F. It prefers a cool to moderate temperature between 50°F and 70°F for optimal growth. These plants are winter hardy and can survive temperatures down to 30°F, but should be protected from extreme heat above 80°F.
PruningPruning Cobweb Houseleek is generally not necessary, but you may remove dead leaves to maintain its appearance. Do this gently, ideally in the spring or early summer. There’s no strict schedule for pruning; it’s more about tidying the plant and encouraging healthy growth.
CleaningAs needed
SoilCobweb houseleek flourishes best in a well-draining soil mix composed of potting soil, coarse sand, and perlite or pumice in equal parts. The ideal pH for this succulent is slightly acidic to neutral, ranging from 6.0 to 7.5. Ensuring the soil is not too rich and has good aeration will help prevent root rot and promote healthy growth.
RepottingCobweb houseleek should be repotted every 2 to 3 years or when the plant outgrows its container. The best time to repot is during the spring or early summer. Use a pot with drainage holes and refresh the soil mix to provide nutrients and encourage growth.
Humidity & MistingCobweb houseleek thrives in dry conditions and does not require high humidity. This plant prefers an environment similar to its native alpine habitat, so aim for lower humidity levels, avoiding excessively moist air to prevent rot and disease.
Suitable locationsIndoor
Place cobweb houseleek in bright, indirect light indoors with good airflow.
Outdoor
Plant in full sun to part shade in well-draining soil outdoors.
Hardiness zone
Cobweb houseleek is suitable for USDA hardiness zones 3-8.
Life cycleCobweb houseleek, Sempervivum arachnoideum L. subsp. tomentosum, begins its life cycle as a seed, which once germinated in well-draining soil and with adequate sunlight, develops into a rosette of succulent leaves covered with a web-like structure of fine white hairs. These rosettes grow by producing offsets, which are small clones that eventually root and develop into new, independent rosettes, thereby expanding the colony. As the plant matures, typically in the summer, it sends up a flower stalk with star-shaped pink or red flowers at the top, which are pollinated by insects. After flowering, the monocarpic rosette that has produced the flower will die, but the plant's life cycle continues through its offsets. The seeds produced from pollination are dispersed, sometimes by wind or rain, to begin new plants. Over the years, the cobweb houseleek continues to thrive by this process of vegetative reproduction and occasional flowering and seed formation.
PropogationPropogation time
Spring to Summer
The Sempervivum arachnoideum L. subsp. tomentosum, commonly known as the Cobweb Houseleek, is typically propagated through offsets. Sempervivums produce small rosette offsets that can be removed from the mother plant once they have developed their own roots. The best time to propagate is during the plant's growing season, which is in the spring or early summer. To propagate, gently twist the offset from the mother plant and allow the cut end to callous for a few days. After the end has calloused, plant the offset in well-draining soil, watering minimally until roots establish. This process allows the plant to quickly produce new, individual plants that are genetically identical to the parent, and it is efficient and straightforward, yielding high success rates for growers.
