Troubleshooting
Cobweb Houseleek problems — and how to fix them
Cobweb Houseleek (Sempervivum arachnoideum) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Crown rot
Water pooling in the webbed rosette or soggy soil. Water at soil level, ensure gritty drainage, and keep the crown dry.
Open, stretched rosettes
Insufficient light. Tight rosettes and heavy webbing require bright direct sun.
Parent rosette dying
Natural, not a fault: it is monocarpic and dies after flowering. Remove the spent rosette and let the offsets fill in.
Mealybugs in the webbing
Pests hide under the hairs and resemble the natural web. Inspect closely and treat with dilute alcohol or insecticidal soap.
Prevent cobweb houseleek problems before they start
Most cobweb houseleek issues are care-mismatch, not bad luck. Dial in the basics:
Looking for cobweb houseleek in general rather than its problems? Read the full cobweb houseleek care guide — light, water, soil and feeding.
Cobweb Houseleek problems — FAQ
Why is my cobweb houseleek crown rot?
Water pooling in the webbed rosette or soggy soil. Water at soil level, ensure gritty drainage, and keep the crown dry.
Why is my cobweb houseleek open, stretched rosettes?
Insufficient light. Tight rosettes and heavy webbing require bright direct sun.
Why is my cobweb houseleek parent rosette dying?
Natural, not a fault: it is monocarpic and dies after flowering. Remove the spent rosette and let the offsets fill in.
Why is my cobweb houseleek mealybugs in the webbing?
Pests hide under the hairs and resemble the natural web. Inspect closely and treat with dilute alcohol or insecticidal soap.