← Species • Family: Crassulaceae 🐾 Pet-Safe

Cobweb Houseleek (Sempervivum arachnoideum)

Sempervivum arachnoideum

Cobweb Houseleek (Sempervivum arachnoideum)

Native to high-altitude rocky screes across the European Alps and Pyrenees, this mat-forming alpine succulent is renowned for its architectural rosettes. Delicate white trichomes stretch between leaf tips, creating a dense cobweb-like canopy that reflects intense UV radiation and minimizes moisture loss. Individual monocarpic rosettes produce starry pink-red flowers on short cymes before dying, having already established a carpet of stoloniferous offsets.

📋 Core Botanical Care Parameters

☀️ Light Requirements

Requires full sun for at least 6 hours daily; intense natural light ensures dense cobweb trichome production and tight rosette formation.

💧 Watering Frequency

Follow the soak-and-dry method; let the substrate dry out completely between waterings and withhold almost all supplemental water during freezing winter dormancy.

🏺 Soil Mix

70% inorganic grit (pumice, crushed lava rock, coarse granite grit) + 30% organic succulent potting soil.

❄️ Cold Tolerance

-30°C (-22°F, USDA Zone 4b)

🌱 Propagation Method

Separation and rooting of stoloniferous offsets ('chicks') in spring or early summer, or by alpine seed sowing.

🐾 Pet Safety

This plant is non-toxic to cats and dogs and safe for pet-friendly homes.

Advertisement
💧

Smart Succulent Watering Calculator

Get a personalized watering schedule based on your plant species, pot, and season:

Botanical Algorithm v2.0
🎯 Recommended Watering Cycle Tailored for your plant
Every 8 - 10 Days

• Dynamically optimized for your pot and climate

Compatible with Google, Apple & Outlook Calendar
🚿
Watering Method: Bottom Watering (Immersion)
⚠️
Golden Rule:

Never water until at least 80% of soil is completely dry!

🌿 Related Succulent & Cactus Species

All Species Profiles →
Echeveria Elegans (Mexican Snowball) 🐾 Pet-Safe Crassulaceae
Echeveria elegans

Echeveria Elegans (Mexican Snowball)

The queen of succulents with silvery blue rosettes. The farina wax layer provides natural sunscreen protection.

❄️ -2°C (USDA Zone 9b) Inspect →
Burro's Tail / Donkey Tail (Sedum morganianum) 🐾 Pet-Safe Crassulaceae
Sedum morganianum

Burro's Tail / Donkey Tail (Sedum morganianum)

Spectacular trailing succulent with weeping stems packed with plump blue-green bead-like leaves.

❄️ 4°C (Frost tender, keep in… Inspect →
Jade Plant / Money Tree (Crassula ovata) ⚠️ Toxic to Pets Crassulaceae
Crassula ovata

Jade Plant / Money Tree (Crassula ovata)

Tree-like woody stems with glossy jade-green leaves, iconic symbol of prosperity and endurance.

❄️ 0°C (Protect from freezing) Inspect →
Advertisement

📖 Related Botanical Care Guides

All Care Guides →
Black-Eyed Susan (Rudbeckia fulgida var. sullivantii 'Goldsturm'): Complete Care & Growing Guide Succulent Varieties 8 min read
12 Nov 2026 • Rıfat Özkan Rıfat Özkan

Black-Eyed Susan (Rudbeckia fulgida var. sullivantii 'Goldsturm'): Complete Care & Growing Guide

Bridging the gap between sweeping North American prairies and refined succulent rockeries, Rudbeckia fulgida var. sullivantii 'Goldsturm' (Black-Eyed Susan) is revered for its extraordinary drought tolerance and striking golden-yellow rays. In this comprehensive guide, we dissect its botanical anatomy, irrigation dynamics, root physiology, and propagation protocols.

Cobweb Houseleek (Sempervivum arachnoideum subsp. tomentosum): Rot, Fungus & Pest Revival Guide Troubleshooting & Pests 9 min read
07 Nov 2026 • Rıfat Özkan Rıfat Özkan

Cobweb Houseleek (Sempervivum arachnoideum subsp. tomentosum): Rot, Fungus & Pest Revival Guide

The Cobweb Houseleek (Sempervivum arachnoideum subsp. tomentosum) is among nature's hardiest alpine succulents, sheltered by a dense web of woolly trichomes. However, this intricate silken coating can trap excess moisture, turning into a fatal breeding ground for fungal pathogens and mealybugs. In this comprehensive rescue guide, discover scientific botanical interventions to cure root rot, eliminate hidden pests, and successfully rehabilitate your prized houseleek.

Advertisement
Member Member Member Rıfat Özkan
Growing Together with 12,000+ Plant Lovers

Weekly Succulent Newsletter

Receive expert plant tips, watering schedules, and rare species care straight to your inbox.

🔒 Zero Spam • Once weekly digest • Unsubscribe with one click anytime.

🌱
Botanical Tip of the Day Verified Botanical Fact

Wait until soil is completely dry: Succulents perish from overwatering, rarely from drought! 🌿