Repotting guide

When & how to repot Hairy Stonecrop (Prometheum pilosum)

Also called Hairy Stonecrop, Hairy Rosularia.

More about hairy stonecrop

About Hairy Stonecrop

Prometheum pilosum · also called Hairy Stonecrop, Hairy Rosularia · houseplant

A charming, miniature biennial (or short-lived perennial) succulent from the Caucasus Mountains and northeast Turkey, formerly classified as Sedum pilosum. It forms tight, hairy rosettes resembling a small Sempervivum, flowers in its second year, then dies — but produces offsets if conditions suit. Ideal for alpine troughs, gritty pans, and bright windowsills.

Mature size: Rosette 1–2 in diameter (2.5–5 cm); flower stems to 4 in (10 cm) tall

Watch for — Etiolation in winter: Insufficient winter light causes the rosette to lose its tight form. Use a south-facing window or supplement with a grow light to maintain compact growth through the darker months.

How to tell hairy stonecrop needs repotting

Repotting on a calendar is less reliable than reading the plant. For hairy stonecrop, 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 hairy stonecrop

Every 2–3 years, into bone-dry mix. Hairy Stonecrop's growth habit — monocarpic or occasionally short-lived perennial forming a single tight rosette; may produce lateral offsets before or after flowering — sets the pace. A charming, miniature biennial (or short-lived perennial) succulent from the Caucasus Mountains and northeast Turkey, formerly classified as Sedum pilosum. It forms tight, hairy rosettes resembling a small Sempervivum, flowers in its second year, then dies — but produces offsets if conditions suit. Ideal for alpine troughs, gritty pans, and bright windowsills.

What size pot to step hairy stonecrop up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Hairy Stonecrop 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 hairy stonecrop

Spring or summer, while hairy stonecrop 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 hairy stonecrop

Repot dry. Do not water hairy stonecrop 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 sharply drained alpine/gritty 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 hairy stonecrop 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 hairy stonecrop 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 hairy stonecrop

Hairy Stonecrop wants sharply drained alpine/gritty mix. A mix of equal parts coarse grit, perlite, and loam replicates its native limestone scree. Excellent drainage is essential; clay or moisture-retentive mixes are fatal. A top dressing of fine grit around the rosette prevents crown rot. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting hairy stonecrop — frequently asked questions

How often should you repot hairy stonecrop?

Every 2–3 years, into bone-dry mix for hairy stonecrop. Repot hairy stonecrop every 2–3 years into a snug pot of sharply drained alpine/gritty 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 hairy stonecrop need?

When is the best time of year to repot hairy stonecrop?

Should you water hairy stonecrop after repotting?

No — not straight away. Repot hairy stonecrop 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 hairy stonecrop after repotting?

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