Cold hardiness & minimum temperature

Is Stapelia grandiflora (Stapelia grandiflora)cold hardy? Hardiness zone & min temp

Also called large-flowered stapelia, carrion flower.

More about stapelia grandiflora

About Stapelia grandiflora

Stapelia grandiflora · also called large-flowered stapelia, carrion flower · houseplant

Stapelia grandiflora is a clumping stem succulent from South Africa grown for its large, star-shaped, hairy maroon flowers that smell of carrion to lure pollinating flies. The soft, four-angled grey-green stems store water, so it tolerates neglect. Give it bright light, very lean gritty soil, and a strict dry winter rest to flower well indoors.

Cold limit: USDA 10-11 (indoor in most US homes) · RHS H1c (18-27°C)

Watch for — Stem rot: Soft, blackening, mushy stems from overwatering or cold-damp conditions. Cut away rot to clean tissue, let it callus, and re-root healthy segments in dry gritty mix.

What stapelia grandiflora's hardiness rating actually means

Stapelia grandiflora is not cold hardy. It is a tropical houseplant that dies if it is left out through frost — there is no zone where it overwinters outdoors in a UK or cold-US climate. Its RHS rating of H1c means: Warm-temperate — can summer outdoors but must come in well before the first frost. On the US scale that maps to USDA 10-11 (indoor in most US homes) — 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 5 °C (and never frost). Stapelia grandiflora has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for stapelia grandiflora as it gets too cold:

Below about about 5 °C, growth stalls and the leaves start to show cold stress — dark, water-soaked, or yellowing patches.
A single light frost blackens the foliage; a hard freeze kills the whole plant, roots included, and it does not recover.
Even a cold, draughty windowsill or an unheated porch in winter can be enough to damage it permanently.

Can stapelia grandiflora go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 5 °C, in shade or dappled light, hardened off gradually.
Bring it back indoors well before the first autumn frost — do not wait for a frost warning, move it when nights drop toward 10-12 °C.
It will never overwinter outside in a temperate climate; the indoors is its winter home, full stop.

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 stapelia grandiflora can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Stapelia grandiflora hardiness — frequently asked questions

Is stapelia grandiflora cold hardy?

Stapelia grandiflora is not cold hardy. It is a tropical houseplant that dies if it is left out through frost — there is no zone where it overwinters outdoors in a UK or cold-US climate. Indoor-only in almost every home. Stapelia grandiflora can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (indoor in most US homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature stapelia grandiflora can survive?

Minimum survivable temperature is roughly about 5 °C (and never frost). Stapelia grandiflora has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is stapelia grandiflora?

Stapelia grandiflora is rated USDA 10-11 (indoor in most US homes) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can stapelia grandiflora survive winter outside?

It can holiday outdoors in summer once nights are reliably above 5 °C, in shade or dappled light, hardened off gradually. Bring it back indoors well before the first autumn frost — do not wait for a frost warning, move it when nights drop toward 10-12 °C. It will never overwinter outside in a temperate climate; the indoors is its winter home, full stop.

What happens to stapelia grandiflora below its minimum temperature?

Below about about 5 °C, growth stalls and the leaves start to show cold stress — dark, water-soaked, or yellowing patches. A single light frost blackens the foliage; a hard freeze kills the whole plant, roots included, and it does not recover. Even a cold, draughty windowsill or an unheated porch in winter can be enough to damage it permanently.