A natural spider web
White hairs from leaf tips join above the rosette, protecting the centre like a fine net.
Sempervivum arachn. 'rubrum' 8.5cm
Normal price
€4,50
What does the legal guarantee mean for plants?
The legal guarantee concerns the plant’s conformity at delivery. It is not a guarantee of survival or growth for two years. Each issue is assessed taking into account the nature of the plant, its care and the conditions in which it is kept. Your statutory rights remain unaffected.
Sempervivumarachn.'rubrum'
A tiny alpine rosette with serious winter courage ❄️
- Crassulaceae
- Outdoor plant
- Extremely cold hardy
- Cobweb rosettes
- Seasonal red colour
Sempervivum arachn. 'rubrum' is a small alpine succulent with enormous decorative energy: compact rosettes shift through deep green, burgundy and vivid red, while fine white fibres stretch between leaf tips like a natural spider web. As offsets fill the pot, they create a living mosaic of red circles unlike any typical indoor succulent.
Its real value lies in the combination of appearance and resilience: it is built for outdoor life, tolerates deep winter cold when drainage is correct and changes colour with the season. In summer, mature rosettes may raise pink starry flowers before completing their cycle, leaving younger offsets to continue. It is ideal for a balcony, rock garden or as a gift for someone who forgets that not every succulent belongs indoors.
What makes it special
Three details that turn its botanical identity into genuine presence for a collection and interior or outdoor setting.
Red that follows the season
Burgundy and red intensify or soften with light, temperature and growth stage.
A mosaic of offsets
Each mother rosette produces smaller daughters that gradually fill available mineral ground.
Why you will love it: A succulent offering red colour, natural pattern and real outdoor resilience rather than delicate decoration.
In your spacePlacement & plant pairingsWhere it looks its best and which plants complement it
Where it looks its best
Grow it outdoors on a sunny balcony, in a rock garden, shallow terracotta or a trough with exceptional drainage. A low position lets offsets spread, while protection from prolonged winter rain matters more than protection from cold.
Plants that bring out its character
Pair it with plants that genuinely share its light, substrate and seasonal rhythm. Separate pots keep care precise for every plant.
- Sempervivum tectorum — larger green rosettes for scale and shared alpine hardiness.
- Sedum album — a low hardy mat with tiny leaves filling gaps in a rock garden.
- Orostachys spinosa — a cold-hardy geometric rosette in a separate pot with similar winter drainage needs.
Care at a glance
Light
Full sun or a very bright outdoor position, with gradual acclimation after purchase.
Water
Water after the mineral mix dries; avoid persistent winter wet and water held in the crown.
Climate
A hardy outdoor plant that needs winter cold, airflow and exceptional drainage.
Pets & children
No spines or latex, but not sold as edible; prevent uncontrolled chewing.
Selected for this plant
Substrate & nutrition
Detailed careComplete care guideLight, drying cycle, climate, substrate and nutrition in detail
Light and position
Give it genuine outdoor light. Full sun supports tight rosettes and strong colour, but a greenhouse-grown plant should be acclimated over several days to prevent scorch.
Watering correctly
Water thoroughly once the mix dries and allow immediate drainage. Check more often in summer, but winter rain is often the greater risk; prefer a sheltered airy position.
Air and humidity
Cobweb fibres hold droplets, so the rosette must dry quickly in open air. Do not grow it in a closed terrarium or indoors year-round.
Temperature and seasonal rhythm
It follows an outdoor alpine rhythm, tolerating winter cold and renewing rosettes in mild and warm periods. Constant indoor warmth and low light disrupt that cycle.
Substrate
Use a very mineral, gravelly mix in a shallow pot or rock garden with open drainage. It tolerates cold far better than cold combined with saturated roots.
Feeding, repotting and handling
It needs minimal feeding. With new Sybasoil wait about two months, then use Cactus & Succulent Focus very sparingly only in active growth, never to force size.
Botanical identityIdentity & natural originAccepted name, taxonomic history and natural or cultivated origin
‘Rubrum’ with unresolved cultivar status
The name Sempervivum arachnoideum ‘Rubrum’ is consistently used in horticulture for a red form, but its formal cultivar status is recorded as unresolved. No breeder or date should be invented.
An accepted wild species
Sempervivum arachnoideum L. is an accepted wild species in Crassulaceae. Cobweb hairs are a species feature, not an artificial trait created by ‘Rubrum’.
From Spain to the Alps and Apennines
The wild species ranges from northern Spain through the Alps and Apennines on temperate mountain rocks.
From natural habitat to care: ‘Rubrum’ is a cultivated colour selection, so ecological context comes from wild Sempervivum arachnoideum in European mountains. Cold is not the main problem there; drainage around the rosette is. Keep it outdoors with sun, air and protection primarily from prolonged winter wet.
Greenleaf for Plant NerdsScientific details nobody asked forBotanical detail for anyone who wants to understand the science behind the plant
Fibres connect leaf tips
Fine hairs extend from leaf tips and join above the centre to create the characteristic web.
Each rosette is monocarpic
A rosette flowers once and then completes its cycle while daughter rosettes continue the cluster.
Offsets ensure continuity
Stolons and daughter rosettes quickly fill small rocky crevices and replace flowered heads.
Colour is a seasonal signal
Anthocyanins strengthen under high light and lower temperatures, so red colour is not constant year-round.
Frequently asked questions
Useful answers about light, watering, seasonal rhythm and the plant’s correct identity.
01How much direct sun can it take?
Give it genuine outdoor light. Full sun supports tight rosettes and strong colour, but a greenhouse-grown plant should be acclimated over several days to prevent scorch.
02When exactly should it be watered?
Water thoroughly once the mix dries and allow immediate drainage. Check more often in summer, but winter rain is often the greater risk; prefer a sheltered airy position.
03Can it stay indoors?
Not as a permanent position. It is a hardy outdoor alpine plant needing real sun, air and seasonal cold. Indoors it usually opens, fades and weakens.
04Why does one rosette die after flowering?
It is normal: each rosette is monocarpic. Surrounding offsets remain alive and continue the pot, provided the old head is removed once dry.
05What substrate and feeding does it need?
Use a very mineral, gravelly mix in a shallow pot or rock garden with open drainage. It tolerates cold far better than cold combined with saturated roots. It needs minimal feeding. With new Sybasoil wait about two months, then use Cactus & Succulent Focus very sparingly only in active growth, never to force size.
06Is it safe around pets and children?
No spines or latex, but not sold as edible; prevent uncontrolled chewing.
📦 Your plant travels protected
Every order is prepared with care so your plant arrives upright, secure and safe.
Individual protection
Plants in pots with a capacity of 3 litres or more are placed in individual boxes that hold the pot securely and reduce the risk of tipping over.
Sturdy packaging
We use reinforced cardboard designed to protect against impacts and vibration during transport.