Cold hardiness & minimum temperature

Is Cabbage Fern (Aglaomorpha coronans)cold hardy? Hardiness zone & min temp

Also called Crown Basket Fern, Basket Fern, Crowning Polypody.

More about cabbage fern

About Cabbage Fern

Aglaomorpha coronans · also called Crown Basket Fern, Basket Fern · tropical

Aglaomorpha coronans is a large epiphytic fern from tropical Asia, prized for its dramatic, deeply lobed fronds that fan out like a crown. It thrives in bright indirect light with consistently moist, well-draining growing medium and high humidity. Not listed as toxic by the ASPCA — considered pet-safe like most true ferns.

Cold limit: USDA 10-12 (indoor-only in most of the US and UK) · RHS H1C (18-28°C)

Watch for — Frond drop in winter: Normal seasonal slowdown in low light and cool temperatures. Reduce watering and avoid drafts from heating vents.

What cabbage fern's hardiness rating actually means

Cabbage Fern 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 10-12 (indoor-only in most of the US and UK) — 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). Cabbage Fern has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Cabbage Fern hardiness — frequently asked questions

Is cabbage fern cold hardy?

Cabbage Fern 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. Cabbage Fern can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (indoor-only in most of the US and UK)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature cabbage fern can survive?

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

What hardiness zone is cabbage fern?

Cabbage Fern is rated USDA 10-12 (indoor-only in most of the US and UK) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can cabbage fern 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 cabbage fern 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.