Repotting guide

When & how to repot Cobweb Houseleek (Sempervivum arachnoideum)

Also called Cobweb Hens and Chicks.

More about cobweb houseleek

About Cobweb Houseleek

Sempervivum arachnoideum · also called Cobweb Hens and Chicks · houseplant

Cobweb Houseleek forms tight rosettes of green-to-red leaves laced with fine white cobweb-like hairs across the tips, a distinctive alpine trait. It clusters into mats of offset 'chicks', tolerates frost and drought, and dies after flowering while leaving offsets behind. Hardy, low-care, and ASPCA non-toxic to cats and dogs.

Mature size: Individual rosettes 1-3 cm wide; clumps spread to 15-30 cm.

How to tell cobweb houseleek needs repotting

Repotting on a calendar is less reliable than reading the plant. For cobweb houseleek, watch for these signs:

Roots growing out of the drainage holes, or the rootball lifting the plant proud of the rim.
Soil that has shrunk away from the pot sides and no longer holds water.
The pot is unstable because the plant has grown top-heavy.
Old, compacted, broken-down mix that stays wet too long — for a succulent that is a rot risk, so refresh it even if the pot size is fine.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot cobweb houseleek

Every 2–3 years, into bone-dry mix. Cobweb Houseleek's growth habit — monocarpic clustering rosettes; the parent dies after flowering but ever-multiplying offsets ('chicks') keep the colony going indefinitely. — sets the pace. Cobweb Houseleek forms tight rosettes of green-to-red leaves laced with fine white cobweb-like hairs across the tips, a distinctive alpine trait. It clusters into mats of offset 'chicks', tolerates frost and drought, and dies after flowering while leaving offsets behind. Hardy, low-care, and ASPCA non-toxic to cats and dogs.

What size pot to step cobweb houseleek up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Cobweb Houseleek stores water and rots in a large pot of slow-drying soil. A tight terracotta pot that dries fast is far safer than a generous plastic one. Never up-pot a succulent by several sizes.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot cobweb houseleek

Spring or summer, while cobweb houseleek is in active growth and warm, is best — roots recover fastest then, and the plant is not sitting in cool damp soil. Avoid repotting a succulent in winter dormancy.

Step-by-step: repotting cobweb houseleek

Repot dry. Do not water cobweb houseleek for several days first. Working with dry roots and dry mix dramatically lowers the rot risk for a succulent.
Pick a snug, fast-draining pot. Choose terracotta one size up at most, with a drainage hole. Have gritty gritty, fast-draining alpine/succulent mix ready.
Tip it out and clean the roots. Slide the plant out, crumble off the old soil, and trim any black, mushy or dead roots with clean snips.
Pot into dry mix. Set cobweb houseleek at its original depth in dry gritty mix, firming gently. Do not bury the stem deeper than it was.
Wait a week before watering. Leave it completely dry and out of harsh sun for about 7 days so any damaged roots callus. Only then water lightly.

Aftercare

Keep cobweb houseleek completely dry and out of fierce sun for about a week so any nicked roots callus before they meet moisture; watering a freshly repotted succulent is the classic way to rot it. Then resume the normal lean, dry rhythm. Do not fertilise for about 3 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for cobweb houseleek

Cobweb Houseleek wants gritty, fast-draining alpine/succulent mix. Sharp drainage is essential: succulent compost with plenty of grit, perlite or coarse sand, or a gravelly alpine mix. Never use heavy, water-retentive soil. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting cobweb houseleek — frequently asked questions

How often should you repot cobweb houseleek?

Every 2–3 years, into bone-dry mix for cobweb houseleek. Repot cobweb houseleek every 2–3 years into a snug pot of gritty, fast-draining alpine/succulent mix, ideally in spring or summer. Let it sit in dry soil and do not water for about a week afterwards so any nicked roots can callus. Over-potting and watering straight away is what rots succulents.

What size pot does cobweb houseleek need?

When is the best time of year to repot cobweb houseleek?

Should you water cobweb houseleek after repotting?

No — not straight away. Repot cobweb houseleek into dry mix and wait about a week before the first watering so any damaged roots callus over. Watering a freshly repotted succulent is the single most common way to rot one.

Should you fertilise cobweb houseleek after repotting?

Not immediately. Wait about 3 weeks after repotting cobweb houseleek. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.