Cold hardiness & minimum temperature

Is Elise's Cotyledon (Cotyledon elisiae)cold hardy? Hardiness zone & min temp

Also called Elise's Cotyledon.

More about elise's cotyledon

About Elise's Cotyledon

Cotyledon elisiae · also called Elise's Cotyledon · houseplant

Elise's Cotyledon is a lesser-known South African succulent with neat, fleshy, slightly cupped leaves on compact branching stems. Like other members of the genus it produces attractive tubular orange flowers in summer and demands the classic Cotyledon combination of bright light, gritty soil, and restrained watering. An interesting collector's succulent for sunny windowsills.

Cold limit: USDA 10–11 · RHS H1c (8–30°C)

Watch for — Root rot: Overwatering, especially in winter, causes roots to decay. The plant wilts despite moist soil. Unpot, remove rotten roots, dust with fungicidal sulphur powder, and repot in fresh dry mix.

What elise's cotyledon's hardiness rating actually means

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

Concretely, for elise'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 elise'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 elise'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.

Elise's Cotyledon hardiness — frequently asked questions

Is elise's cotyledon cold hardy?

Elise'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. Elise'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 elise's cotyledon can survive?

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

What hardiness zone is elise's cotyledon?

Elise'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 elise'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 elise'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.