Cold hardiness & minimum temperature

Is Sempervivum 'Red Lion' (Sempervivum 'Red Lion')cold hardy? Hardiness zone & min temp

Also called Red Lion houseleek.

More about sempervivum 'red lion'

About Sempervivum 'Red Lion'

Sempervivum 'Red Lion' · also called Red Lion houseleek · houseplant

Sempervivum 'Red Lion' is a striking hybrid houseleek with bold rosettes that flush deep ruby to wine-red in strong sun and cool seasons, fading to bronze-green in shade or warmth. Cold-hardy and drought-tolerant, it offsets freely into colourful colonies. Grown for its intense red tones, it needs full sun, sharp drainage, and minimal water to perform.

Cold limit: USDA 4-8 (hardy outdoors; indoors keep cold and very bright) · RHS H6 (-20 to 27°C)

Watch for — Loss of red colour: The ruby tone depends on full sun, cool temperatures, and lean conditions. In shade, warmth, or with feeding the rosettes turn green; increase light, reduce fertiliser, and accept that summer heat naturally mutes the colour.

What sempervivum 'red lion''s hardiness rating actually means

Yes — sempervivum 'red lion' is genuinely cold hardy. Rated RHS H6 and USDA 4-8 (hardy outdoors; indoors keep cold and very bright), 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 4-8 (hardy outdoors; indoors keep cold and very bright) — 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. Sempervivum 'Red Lion' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for sempervivum 'red lion' 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 sempervivum 'red lion' go outside or overwinter — and where?

Plant it out within USDA 4-8 (hardy outdoors; indoors keep cold and very bright) 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 'red lion' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Sempervivum 'Red Lion' hardiness — frequently asked questions

Is sempervivum 'red lion' cold hardy?

Yes — sempervivum 'red lion' is genuinely cold hardy. Rated RHS H6 and USDA 4-8 (hardy outdoors; indoors keep cold and very bright), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Sempervivum 'Red Lion' is hardy across USDA 4-8 (hardy outdoors; indoors keep cold and very bright); 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 'red lion' can survive?

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

What hardiness zone is sempervivum 'red lion'?

Sempervivum 'Red Lion' is rated USDA 4-8 (hardy outdoors; indoors keep cold and very bright) and RHS H6 — Hardy throughout the UK and northern Europe.

Can sempervivum 'red lion' survive winter outside?

Plant it out within USDA 4-8 (hardy outdoors; indoors keep cold and very bright) 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 'red lion' 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.