Cold hardiness & minimum temperature

Is Sedum telephium 'Purple Emperor' (Hylotelephium telephium 'Purple Emperor')cold hardy? Hardiness zone & min temp

Also called Purple Emperor stonecrop.

More about sedum telephium 'purple emperor'

About Sedum telephium 'Purple Emperor'

Hylotelephium telephium 'Purple Emperor' · also called Purple Emperor stonecrop · flowering

A dark-leaved orpine stonecrop grown for dramatic deep purple-black succulent foliage that contrasts with clusters of dusky-pink star flowers in late summer. 'Purple Emperor' adds rich color and structure to sunny borders, attracts bees and butterflies, and stays relatively compact and sturdy when grown lean.

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

Watch for — Crown rot: Soggy winter soil rots the succulent base; plant in sharply drained ground and keep the crown dry in winter.

What sedum telephium 'purple emperor''s hardiness rating actually means

Yes — sedum telephium 'purple emperor' 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. Sedum telephium 'Purple Emperor' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for sedum telephium 'purple emperor' 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 sedum telephium 'purple emperor' 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 sedum telephium 'purple emperor' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Sedum telephium 'Purple Emperor' hardiness — frequently asked questions

Is sedum telephium 'purple emperor' cold hardy?

Yes — sedum telephium 'purple emperor' 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. Sedum telephium 'Purple Emperor' 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 sedum telephium 'purple emperor' can survive?

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

What hardiness zone is sedum telephium 'purple emperor'?

Sedum telephium 'Purple Emperor' is rated USDA 3-9 and RHS H7 — Hardy in the severest European continental winters.

Can sedum telephium 'purple emperor' 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 sedum telephium 'purple emperor' 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.