Common Name: Cobweb Houseleek
 
Description: Sempervivum arachnoideum, commonly known as Cobweb Houseleek, is a fascinating succulent native to the mountainous regions of Europe. This hardy perennial is characterized by its rosettes of fleshy, pointed leaves that form clusters. The leaves are typically green, adorned with fine, white hairs that give the plant a distinctive cobweb-like appearance. Each rosette can grow up to 10 cm (4 inches) in diameter, and the plant can reach a height of about 15 cm (6 inches). In summer, it produces star-shaped pink or red flowers on slender stalks, adding a lovely burst of color to its striking foliage.
 
Care Requirements
Light:
Optimal: Full sun to partial shade.
Tolerates: Direct sunlight but may need some protection in very hot climates.
Tip: Aim for at least 6 hours of sunlight daily for optimal growth.
 
Water:
Frequency: Allow the soil to dry completely between waterings.
Method: Water thoroughly, ensuring excess drains out; do not let the plant sit in water.
Seasonal Adjustment: Water less frequently in winter, as growth slows.
 
Soil:
Type: Well-draining cactus or succulent potting mix.
Amendments: Consider adding sand or perlite to improve drainage.
 
Temperature & Humidity:
Ideal Range: 15°C to 25°C (59°F to 77°F).
Minimum: Can tolerate temperatures as low as -10°C (14°F) for short periods.
Humidity: Prefers low humidity; thrives in dry conditions.
 
Fertilization:
Frequency: Fertilize sparingly during the growing season (spring and summer), about once a month.
Type: Use a diluted, balanced fertilizer or a cactus-specific fertilizer.
 
Propagation:
Methods: Best propagated by offsets (pups) or leaf cuttings.
Process: Allow offsets to dry for a day or two before planting in well-draining soil.
 
Pests & Problems:
Common Pests: Mealybugs, aphids, and slugs.
Issues: Overwatering can lead to root rot; ensure proper drainage.
Solution: Treat pests with insecticidal soap or neem oil if necessary.
 
Repotting:
Frequency: Every 2-3 years or when the plant outgrows its pot.
Signs: Roots emerging from the drainage holes or a pot-bound appearance.
 
Additional Tips
Rotate the plant occasionally to promote even growth.
Monitor for signs of stress, such as wilting or discoloration, to adjust care as needed.
This resilient succulent is excellent for rock gardens, container arrangements, or as ground cover in well-drained areas.
 
With proper care, Sempervivum arachnoideum can thrive and add a unique, charming element to your succulent collection!