Cold hardiness & minimum temperature

Is Sempervivum heuffelii (Sempervivum heuffelii)cold hardy? Hardiness zone & min temp

Also called Heuffel's houseleek, Jovibarba heuffelii.

More about sempervivum heuffelii

About Sempervivum heuffelii

Sempervivum heuffelii · also called Heuffel's houseleek, Jovibarba heuffelii · houseplant

Sempervivum heuffelii (also classified as Jovibarba heuffelii), Heuffel's houseleek, is a fully cold-hardy alpine succulent forming flat rosettes of pointed leaves in greens, bronzes and reds, often with fine ciliate hairs. Unusually for the genus, it does not produce stoloned chicks but divides by splitting the rosette itself. It thrives on neglect, full sun and sharp drainage, and is happiest grown cool.

Cold limit: USDA 4-8 (fully frost-hardy; an outdoor alpine, not a warm houseplant) · RHS H7 (Tolerates roughly -20 to 27°C; grows best cool)

Watch for — Rot from winter wet: Cold combined with soggy soil is the main killer. Ensure extremely sharp drainage and keep nearly dry in winter; remove any mushy, blackened rosettes.

What sempervivum heuffelii's hardiness rating actually means

Yes — sempervivum heuffelii is genuinely cold hardy. Rated RHS H7 and USDA 4-8 (fully frost-hardy; an outdoor alpine, not a warm houseplant), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H7 means: Hardy in the severest European continental winters. On the US scale that maps to USDA 4-8 (fully frost-hardy; an outdoor alpine, not a warm houseplant) — 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 below about −20 °C. Sempervivum heuffelii is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for sempervivum heuffelii as it gets too cold:

It tolerates winter lows to about −20 °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 sempervivum heuffelii go outside or overwinter — and where?

Plant it out within USDA 4-8 (fully frost-hardy; an outdoor alpine, not a warm houseplant) 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 sempervivum heuffelii can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Sempervivum heuffelii hardiness — frequently asked questions

Is sempervivum heuffelii cold hardy?

Yes — sempervivum heuffelii is genuinely cold hardy. Rated RHS H7 and USDA 4-8 (fully frost-hardy; an outdoor alpine, not a warm houseplant), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Sempervivum heuffelii is hardy across USDA 4-8 (fully frost-hardy; an outdoor alpine, not a warm houseplant); 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 sempervivum heuffelii can survive?

Minimum survivable temperature is roughly below about −20 °C. Sempervivum heuffelii is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is sempervivum heuffelii?

Sempervivum heuffelii is rated USDA 4-8 (fully frost-hardy; an outdoor alpine, not a warm houseplant) and RHS H7 — Hardy in the severest European continental winters.

Can sempervivum heuffelii survive winter outside?

Plant it out within USDA 4-8 (fully frost-hardy; an outdoor alpine, not a warm houseplant) 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 sempervivum heuffelii below its minimum temperature?

It tolerates winter lows to about −20 °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.