Cold hardiness & minimum temperature

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

Also called Red Ice Plant, Hardy Ice Plant.

More about dyer's ice plant

About Dyer's Ice Plant

Delosperma dyeri · also called Red Ice Plant, Hardy Ice Plant · houseplant

Dyer's Ice Plant is a low-growing South African succulent in the Aizoaceae family, prized for its vivid scarlet-red daisy-like flowers. It thrives in full sun with very little water and excellent drainage. Best suited to rock gardens, sunny windowsills, or container culture. Not listed as toxic by the ASPCA; considered pet-safe.

Cold limit: USDA 6-9 · RHS H4 (5-30°C)

Watch for — Etiolation: Stretched, pale growth indicates insufficient light. Move to a sunnier position or supplement with a grow light during short winter days.

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

Yes — dyer'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. Dyer's Ice Plant is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for dyer'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 dyer'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 dyer'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.

Dyer's Ice Plant hardiness — frequently asked questions

Is dyer's ice plant cold hardy?

Yes — dyer'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. Dyer'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 dyer's ice plant can survive?

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

What hardiness zone is dyer's ice plant?

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

Can dyer'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 dyer'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.