Cold hardiness & minimum temperature

Is Stonecrop 'Autumn Joy' (Hylotelephium spectabile)cold hardy? Hardiness zone & min temp

Also called Autumn Joy Sedum, Ice Plant, Showy Stonecrop.

More about stonecrop 'autumn joy'

About Stonecrop 'Autumn Joy'

Hylotelephium spectabile · also called Autumn Joy Sedum, Ice Plant · flowering

Hylotelephium 'Autumn Joy' (formerly Sedum spectabile) is a robust, late-season perennial with large flat-topped flower heads that open dusty pink in late summer and deepen to copper-red by autumn. It is drought-tolerant, thriving in full sun and well-drained soil, and is highly attractive to pollinators. Sedum/Hylotelephium is considered pet-safe by the ASPCA.

Cold limit: USDA 3-9 · RHS H7 (-30-30°C)

Watch for — Crown rot in winter: Standing water around the crown in winter causes fungal rot; ensure drainage is excellent, especially in heavier soils.

What stonecrop 'autumn joy''s hardiness rating actually means

Yes — stonecrop 'autumn joy' 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. Stonecrop 'Autumn Joy' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for stonecrop 'autumn joy' 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 stonecrop 'autumn joy' 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 stonecrop 'autumn joy' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Stonecrop 'Autumn Joy' hardiness — frequently asked questions

Is stonecrop 'autumn joy' cold hardy?

Yes — stonecrop 'autumn joy' 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. Stonecrop 'Autumn Joy' 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 stonecrop 'autumn joy' can survive?

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

What hardiness zone is stonecrop 'autumn joy'?

Stonecrop 'Autumn Joy' is rated USDA 3-9 and RHS H7 — Hardy in the severest European continental winters.

Can stonecrop 'autumn joy' 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 stonecrop 'autumn joy' 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.