Cold hardiness & minimum temperature

Is Houseleek Cliff Stonecrop (Prometheum sempervivoides)cold hardy? Hardiness zone & min temp

Also called Houseleek Cliff Stonecrop, Rosularia sempervivoides.

More about houseleek cliff stonecrop

About Houseleek Cliff Stonecrop

Prometheum sempervivoides · also called Houseleek Cliff Stonecrop, Rosularia sempervivoides · houseplant

A tough alpine succulent native to rocky stony slopes from Turkey through the Caucasus, Armenia, and northern Iran at altitudes up to 2,900 m. Its tight flat rosettes of pointed, finely hairy leaves closely resemble houseleeks (Sempervivum). Fiery red flowers appear on short stems in summer. Extremely cold hardy; ideal for rock gardens, troughs, or alpine collections.

Cold limit: USDA 5–8 · RHS H6 (-25 to 25°C)

Watch for — Winter rot in wet conditions: Even though it is frost hardy, wet winter soil combined with cold causes crown rot. Ensure sharp drainage year-round; a gravel mulch around rosettes helps shed moisture away from the crown.

What houseleek cliff stonecrop's hardiness rating actually means

Yes — houseleek cliff stonecrop is genuinely cold hardy. Rated RHS H6 and USDA 5–8, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H6 means: Hardy throughout the UK and northern Europe. On the US scale that maps to USDA 5–8 — the zones where it can be left outdoors year-round.

New to these scales? The USDA hardiness zone map explained covers how the zone numbers work, and you can find your own zone with the zone finder.

Minimum temperature — and what happens below it

Minimum survivable temperature is roughly about −20 to −15 °C. Houseleek Cliff Stonecrop is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for houseleek cliff stonecrop as it gets too cold:

It tolerates winter lows to about −20 to −15 °C once established.
Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root.
First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.

Can houseleek cliff stonecrop go outside or overwinter — and where?

Plant it out within USDA 5–8 and it overwinters with little or no help.
It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy.
The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

Work back from your local frost dates with the frost-date calculator: the last spring frost and first autumn frost are what really decide when houseleek cliff stonecrop can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Houseleek Cliff Stonecrop hardiness — frequently asked questions

Is houseleek cliff stonecrop cold hardy?

Yes — houseleek cliff stonecrop is genuinely cold hardy. Rated RHS H6 and USDA 5–8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Houseleek Cliff Stonecrop is hardy across USDA 5–8; it belongs in the ground or a frost-proof container, not on a windowsill, and many types actively need a cold winter to perform.

What is the minimum temperature houseleek cliff stonecrop can survive?

Minimum survivable temperature is roughly about −20 to −15 °C. Houseleek Cliff Stonecrop is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is houseleek cliff stonecrop?

Houseleek Cliff Stonecrop is rated USDA 5–8 and RHS H6 — Hardy throughout the UK and northern Europe.

Can houseleek cliff stonecrop survive winter outside?

Plant it out within USDA 5–8 and it overwinters with little or no help. It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy. The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

What happens to houseleek cliff stonecrop below its minimum temperature?

It tolerates winter lows to about −20 to −15 °C once established. Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root. First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.