Cold hardiness & minimum temperature

Is Ice Plant (Sedum spectabile)cold hardy? Hardiness zone & min temp

Also called Ice Plant, Showy Stonecrop, Butterfly Stonecrop.

More about ice plant

About Ice Plant

Sedum spectabile · also called Ice Plant, Showy Stonecrop · flowering

Sedum spectabile (now often listed as Hylotelephium spectabile) is a clump-forming border perennial with fleshy, pale blue-green leaves and large flat-topped corymbs of rose-pink star flowers in late summer and autumn. Exceptionally drought-tolerant, it thrives in full sun and lean soil, and its dried seedheads extend winter interest while feeding birds.

Cold limit: USDA 3-9 · RHS H7 (-34 to 32°C)

Watch for — Crown and stem rot: Wet winters or poor drainage are the most common killer. Plant on a slope or raised bed, and incorporate grit when planting. Avoid mulching directly against the crown.

What ice plant's hardiness rating actually means

Yes — ice plant is genuinely cold hardy. Rated RHS H7 and USDA 3-9, 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 3-9 — 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. Ice Plant is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for ice plant 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 ice plant go outside or overwinter — and where?

Plant it out within USDA 3-9 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 ice plant can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Ice Plant hardiness — frequently asked questions

Is ice plant cold hardy?

Yes — ice plant is genuinely cold hardy. Rated RHS H7 and USDA 3-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Ice Plant is hardy across USDA 3-9; 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 ice plant can survive?

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

What hardiness zone is ice plant?

Ice Plant is rated USDA 3-9 and RHS H7 — Hardy in the severest European continental winters.

Can ice plant survive winter outside?

Plant it out within USDA 3-9 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 ice plant 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.