Cold hardiness & minimum temperature

Is Stonecrop Rosularia (Rosularia sedoides)cold hardy? Hardiness zone & min temp

Also called Stonecrop Rosularia, Sedum-like Rosularia.

More about stonecrop rosularia

About Stonecrop Rosularia

Rosularia sedoides · also called Stonecrop Rosularia, Sedum-like Rosularia · houseplant

Rosularia sedoides is a petite Crassulaceae succulent native to rocky hillsides of Turkey and the Middle East, forming tight rosettes of bluish-green, glandular-hairy leaves. White or pale pink flowers appear in summer. It performs best in sharply draining, gritty soil with full sun and is suited to alpine troughs, rocky walls, or sunny windowsills.

Cold limit: USDA 6–9 · RHS H5 (-5–28°C)

Watch for — Crown rot in wet winters: The most significant threat. Water pooling in the rosette centre in cold, damp conditions rapidly kills the plant. Grow in raised beds, troughs with overhang protection, or bring pots under cover in wet winters.

What stonecrop rosularia's hardiness rating actually means

Yes — stonecrop rosularia is genuinely cold hardy. Rated RHS H5 and USDA 6–9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H5 means: Hardy in most of the UK and in cold winters. On the US scale that maps to USDA 6–9 — 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 about −15 to −10 °C. Stonecrop Rosularia is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for stonecrop rosularia as it gets too cold:

It tolerates winter lows to about −15 to −10 °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 rosularia go outside or overwinter — and where?

Plant it out within USDA 6–9 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 rosularia can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Stonecrop Rosularia hardiness — frequently asked questions

Is stonecrop rosularia cold hardy?

Yes — stonecrop rosularia is genuinely cold hardy. Rated RHS H5 and USDA 6–9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Stonecrop Rosularia is hardy across USDA 6–9; 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 rosularia can survive?

Minimum survivable temperature is roughly about −15 to −10 °C. Stonecrop Rosularia is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is stonecrop rosularia?

Stonecrop Rosularia is rated USDA 6–9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can stonecrop rosularia survive winter outside?

Plant it out within USDA 6–9 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 rosularia below its minimum temperature?

It tolerates winter lows to about −15 to −10 °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.