Sempervivum Arachnoideum Plant Care: How To Grow Cobweb Houseleek

Sempervivum arachnoideum [sem-per-VEE-vum, a-rak-NOY-dee-um] is a species of flowering plants in the family Crassulaceae originating from Europe, the Alps, Carpathians, and the Apennines.

The name or the genus translates to ‘always alive spider web.’

Cobweb spider web succulent aka Sempervivum ArachnoideumPin

This translation is a perfect representation of the succulent as it’s an evergreen perennial, producing a mat of fleshy green or reddish-green rosettes with white cobweb-like hairs at the top.

Common names include:

  • Cobweb Houseleek
  • Cobweb Hens and Chicks
  • Cobweb Sedum
  • Cebenese

Sempervivum Arachnoideum Care

Size and Growth

Sempervivum arachnoideum cobweb is a low-growing succulent reaching a height of about 3” inches.

Each rosette measures about 1” – 1.5” inch in diameter, whereas the entire plant spreads approximately 8” – 12” inches wide.

The mother rosette, known as the Hen, spreads in a circular pattern by growing horizontal stems in every direction.

These stems produce new rosettes called offsets or chicks.

Each new rosette becomes independent of the mother rosette by developing its own root system before detaching itself from the connecting stolon.

Cobweb hens and chicks are relatively fast-growing succulent, but it is monocarpic, which means it dies after flowering.

However, this does not affect the overall beauty of the plant as there are several offsets to replace the dead rosettes and fill any gaps created.

Flowering and Fragrance

Sempervivum arachnoideum blooms excessively from mid to late summer when fancy pink flowers dominate over the short, fleshy foliage.

The Hen rosette produces a thick pinkish-red flowering stalk bearing a star-shaped flower with bright pink petals.

‘Cebenese’ has a webbed rosette that does very well in cold climates, even buried under snow! It grows best outdoors and has pink edges.

Some varieties produce pale yellow flowers instead of the usual pink blooms.

The starry flowers growing on tight clusters of rosettes measure about half an inch wide.

They grow in flat cymes on narrow stems reaching up to 5” inches high.

Lighting Requirements and Temperature

Like most hardy succulents, Sempervivums require full sun but can perform well in partial light shade as long as it receives sufficient sun exposure every day.

It is hardy in USDA hardiness zones 5 to 8 and grows best in the south and west-facing aspects.

To determine if a plant is a sufficiently cold hardy, the USDA created numbered zones indicating winter low temperatures; the lower the zone number, the colder the winter. 

Cobweb sedum is cold hardy, and tolerates temperatures down to -25° degrees Fahrenheit (-32° C).

Watering and Feeding

The best practice for watering cobweb hens and chicks is to use the ‘soak and dry’ method.

Water the plant sufficiently and let the soil dry out completely on this drought tolerant plant before watering it again.

Chicks Sempervivum arachnoideum needs to be watered periodically in the flowering season and once in a while during the winter months.

The plant doesn’t need feeding, but repotting it in well-draining succulent potting soil containing compost mixed with a slow-release fertilizer ensures a long and healthy plant life.

Soil and Transplanting

Arachnoideum is a low-maintenance but resilient succulent and performs well in a wide range of climates.

It is quick to adapt to local conditions, although it prefers well-drained and sandy soil types. When planting in pots use a container with drainage holes and succulent soil mix.

The ideal soil pH should be between 6 to 8. For best results, grow Sempervivum arachnoideum in full sun in well-drained soil, preferably in containers with added horticultural grit to aid drainage. 

More on making a well drained succulent potting mix.

Grooming and Maintenance

Once established, S. arachnoideum hens and chicks require little to no maintenance.

Its fibrous root system holds the soil in place even when grown in vertical plantings.

At the end of the flowering season, the plant needs to be deadheaded.

The matured and spent rosettes and blooms should be carefully removed in order to make room for new ones to grow.

How To Propagate Cobweb Sempervivum?

The Cebenese succulent is propagated by root offsets or seeds sown in spring.

The ideal way of propagation is through pups and offsets. If given proper care, Sempervivum arachnoideum thrives beautifully at a fast pace.

It is not suitable for indoor plantation unless kept in a spot where it receives direct sunlight for at least 6 hours a day.

To propagate a new plant, gently remove the chick or baby rosette growing near the main plant (hen).

Carefully transfer it to the desired location and press the soil slightly to hold the baby rosette in place.

Arachnoideum Sempervivum Pests or Diseases

Sempervivum arachnoideum is resistant to most of the common garden pests and diseases.

However, it is susceptible to rust, root rot, vine weevil, and leaf rot.

Cobweb houseleek is known to attract butterflies. When planting these evergreen charmers, be prepared to welcome fluttering beauties into your garden.

Cobweb succulent is safe to grow in homes and full sun gardens.

Although it is not an edible plant, Cobweb succulent (hens and chicks) is not poisonous and will not cause any harm if ingested by pets or humans.

No toxicity has been reported for this succulent, but it is likely to cause nausea, vomiting, and diarrhea if ingested considerably.

Sempervivum Arachnoideum Hens and Chicks Uses

Fleshy green rosettes adorned with white hair and distinct pink blooms. The arachnoideum Sempervivum is an excellent choice for dry and stony places such as rock gardens, crevice gardens, and trough gardens.

Use it to decorate the cracks in dry stone walls and plant it in front of garden beds and borders to give the place a touch of uniqueness.

Sempervivum arachnoideum provides good ground cover when planted closely together in large numbers.

This variety is a must-have for Mediterranean gardens and is perfect for edge plantations, be it in garden beds, troughs, or even containers.

Plant Arachnoideum hens and chicks separately in small clay pots using well-drained soil and place them in full sun or on the windowsill for a dazzling display or use to fill Sempervivum walls, mosaics, and topiary.

Pair it with other similar varieties to make a truly stunning succulent collection.

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