Cold hardiness & minimum temperature

Is Wood's Cotyledon (Cotyledon woodii)cold hardy? Hardiness zone & min temp

Also called Wood's Cotyledon, Woody Cotyledon.

More about wood's cotyledon

About Wood's Cotyledon

Cotyledon woodii · also called Wood's Cotyledon, Woody Cotyledon · houseplant

Wood's Cotyledon is a slender-stemmed South African cliff-dweller with small, fleshy, spoon-shaped leaves neatly arranged on trailing or pendant stems. It is particularly valued as a hanging-basket succulent, producing pendulous orange tubular flowers in summer. Drought-tolerant and compact, it thrives with minimal fuss in a bright, airy spot.

Cold limit: USDA 10–11 · RHS H1c (8–32°C)

Watch for — Stem dieback at joints: Sections of stem turn brown and dry, often at leaf nodes. Usually caused by overwatering or cold damage. Prune back to healthy tissue and adjust care; the plant typically rebounds with new side shoots.

What wood's cotyledon's hardiness rating actually means

Wood's Cotyledon 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 — 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). Wood's Cotyledon has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for wood's cotyledon 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 wood's cotyledon 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 wood's cotyledon can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Wood's Cotyledon hardiness — frequently asked questions

Is wood's cotyledon cold hardy?

Wood's Cotyledon 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. Wood's Cotyledon can only live outside year-round in genuinely frost-free climates (roughly USDA 10–11); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature wood's cotyledon can survive?

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

What hardiness zone is wood's cotyledon?

Wood's Cotyledon is rated USDA 10–11 and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can wood's cotyledon 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 wood's cotyledon 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.