Cold hardiness & minimum temperature

Is Sutherland's Ice Plant (Delosperma sutherlandii)cold hardy? Hardiness zone & min temp

Also called Sutherland's Delosperma, Hardy Pink Ice Plant.

More about sutherland's ice plant

About Sutherland's Ice Plant

Delosperma sutherlandii · also called Sutherland's Delosperma, Hardy Pink Ice Plant · houseplant

Sutherland's Ice Plant is a hardy South African succulent producing a profusion of vivid pink-purple daisy-like flowers from spring to autumn. Its fleshy, cylindrical leaves form dense, low mats suited to rock gardens and sunny containers. One of the hardier Delosperma species, tolerating light frosts. Non-toxic and pet-safe.

Cold limit: USDA 6-9 · RHS H4 (0-28°C)

Watch for — Root rot in wet winters: Cold, wet soil in winter is the most common cause of plant death. Ensure excellent drainage, and in very wet climates consider a gravel mulch or moving containers under cover.

What sutherland's ice plant's hardiness rating actually means

Yes — sutherland's ice plant is genuinely cold hardy. Rated RHS H4 and USDA 6-9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H4 means: Hardy in an average winter across much of the temperate world. 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 −10 to −5 °C. Sutherland's Ice Plant is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for sutherland's ice plant as it gets too cold:

It tolerates winter lows to about −10 to −5 °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 sutherland's ice plant 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 sutherland's ice plant can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Sutherland's Ice Plant hardiness — frequently asked questions

Is sutherland's ice plant cold hardy?

Yes — sutherland's ice plant is genuinely cold hardy. Rated RHS H4 and USDA 6-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Sutherland's Ice Plant 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 sutherland's ice plant can survive?

Minimum survivable temperature is roughly about −10 to −5 °C. Sutherland's Ice Plant is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is sutherland's ice plant?

Sutherland's Ice Plant is rated USDA 6-9 and RHS H4 — Hardy in an average winter across much of the temperate world.

Can sutherland's ice plant 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 sutherland's ice plant below its minimum temperature?

It tolerates winter lows to about −10 to −5 °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.