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Sempervivum arachnoideum: The Fascinating Cobweb Houseleek

Sempervivum arachnoideum is a captivating species of succulent that boasts a unique and intriguing feature – its rosettes are covered with a delicate white web, resembling a spider’s creation. Such a characteristic is rarely found in other plants, making this species a true wonder of nature. With an average size of 1.5 inches, it thrives on rocky terrains in the mountains of Europe and has adapted remarkably well to various soil types, displaying excellent resistance to drought conditions.

The leaves of Sempervivum arachnoideum are small but succulent, which allows for a higher leaf count compared to other species. One of the most exciting aspects of this plant is the diversity of its varieties. Among them, some display striking red leaves, creating a stunning contrast when combined with the white web.

During the spring season, Sempervivum arachnoideum experiences vigorous growth, resulting in the formation of a dense web. However, as the season progresses, the web gradually diminishes, adding another fascinating dimension to this plant’s life cycle.

When cultivated properly, Sempervivum arachnoideum quickly forms small hills adorned with rosettes, making it a great choice for container gardening due to its compact size.

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Cobweb Houseleek Care

Like all sempervivums, the cobweb houseleek thrives in sunny locations and prefers well-draining soil that does not retain stagnant water. It can flourish even in poor soil conditions, and for heavy clay soils, adding some sand can improve their texture and drainage.

This species is highly frost-resistant and requires minimal watering during drought periods, showcasing its ability to withstand adverse weather conditions.

How often do you water Sempervivum arachnoideum?

During the growing season, which typically spans from spring to fall, you should water the plant sparingly, allowing the soil to dry out between waterings. Depending on the climate and environmental conditions, this might mean watering once every two to three weeks or even less frequently. It’s essential to monitor the soil’s moisture level and only water when it has completely dried out.

In contrast, during the winter months, when the plant goes into a period of dormancy, it requires even less water. In many cases, you may not need to water at all during this period, as the plant can draw on its stored water reserves.


Sempervivum arachnoideum ssp. arachnoideum: Commonly found in the mountains of France and Spain, this subspecies displays rosettes with a diameter of about 0.5 inches.

Sempervivum arachnoideum ssp. tomentosum: This subspecies can be found in southern Europe and features slightly larger rosettes, with a diameter of up to 1.5 inches.

Notable Cultivars

Sempervivum Prosecco

The center rosette of this cultivar is purple, with light olive tips, creating a beautiful color contrast, complemented by the snow-white web and delicate white hairs covering the leaves. It maintains its color throughout the season and grows vigorously, reaching a diameter of 2 inches. It originates from the Aaliyah variety.

Sempervivum Maren

This cultivar exhibits a bright red color in spring, contrasting with the white hairs at the leaf tips. As a larger variety of Sempervivum arachnoideum, its rosettes can reach a diameter of 3 inches. In summer, the leaves transition to an orange hue with a green center rosette. It grows rapidly, producing numerous daughter plants, and its flowers are a lovely pink shade. It was bred in Germany in 2002 by Volkmar Shara, originating from the S. Apache variety.

Sempervivum Georgette

Featuring green-red leaves and rosettes measuring 1.5 inches in diameter, this beautiful variety is not as common among collectors. It was bred in the United Kingdom by David T. Ford in 1972 through the crossbreeding of Jubilee and Red Mountain varieties.

Sempervivum Early Winter

Unlike most Sempervivum arachnoideum varieties, this one boasts a lush web. It produces white flowers in June, creating a stunning contrast with its green rosettes. The plant’s diameter is 1 inch, and it was bred in Germany by Volkmar Schara in 2010, originating from the parent variety Baby Boo.

Sempervivum Ginnie’s Delight

This cultivar exhibits red leaves with green tips and is adorned with silver hairs. It shows vigorous growth and is especially spectacular during the spring season. With an average size of 1.5-2 inches, it has a moderate growth rate.


In conclusion, Sempervivum arachnoideum is a captivating and versatile succulent species, offering a range of unique varieties to delight gardening enthusiasts. Its adaptability to different soil types and resilience to harsh weather conditions make it a popular choice for both outdoor and container gardening. Whether you’re a collector or a novice gardener, the cobweb houseleek is sure to add a touch of charm and wonder to any garden or indoor space.