Cold hardiness & minimum temperature

Is Alocasia Cuprea (Red Secret) (Alocasia cuprea)cold hardy? Hardiness zone & min temp

Also called Red Secret, Mirror Plant, Jewel Alocasia, Copper Alocasia, Elephant Ear.

More about alocasia cuprea (red secret)

About Alocasia Cuprea (Red Secret)

Alocasia cuprea · also called Red Secret, Mirror Plant · houseplant

Alocasia cuprea 'Red Secret' is a compact jewel aroid prized for thick, metallic copper-to-deep-red leaves with a mirror-like sheen. Give it bright indirect light, evenly moist (never soggy) well-draining soil, warmth and high humidity above 60%. It is toxic to cats and dogs per the ASPCA, containing insoluble calcium oxalates.

Cold limit: USDA 10-11 (grow indoors or in a greenhouse in cooler climates; outdoors only in frost-free regions) (18-24C)

Watch for — Yellowing leaves and root rot: Usually overwatering or poor drainage. Let the top inch or two dry between waterings, ensure a chunky free-draining mix and a pot with drainage holes, and cut back water in winter.

What alocasia cuprea (red secret)'s hardiness rating actually means

Alocasia Cuprea (Red Secret) 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 (grow indoors or in a greenhouse in cooler climates; outdoors only in frost-free regions) — 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). Alocasia Cuprea (Red Secret) has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for alocasia cuprea (red secret) 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 alocasia cuprea (red secret) 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 alocasia cuprea (red secret) can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Alocasia Cuprea (Red Secret) hardiness — frequently asked questions

Is alocasia cuprea (red secret) cold hardy?

Alocasia Cuprea (Red Secret) 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. Alocasia Cuprea (Red Secret) can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (grow indoors or in a greenhouse in cooler climates; outdoors only in frost-free regions)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature alocasia cuprea (red secret) can survive?

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

What hardiness zone is alocasia cuprea (red secret)?

Alocasia Cuprea (Red Secret) is rated USDA 10-11 (grow indoors or in a greenhouse in cooler climates; outdoors only in frost-free regions) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can alocasia cuprea (red secret) 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 alocasia cuprea (red secret) 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.