Cold hardiness & minimum temperature

Is Calathea (Calathea (Goeppertia) spp.)cold hardy? Hardiness zone & min temp

Also called prayer-plant cousin, peacock plant, rattlesnake plant.

About Calathea

Calathea (Goeppertia) spp. · also called prayer-plant cousin, peacock plant · tropical

Calathea is the drama queen of the Marantaceae family — exquisite patterned leaves paired with strict demands for high humidity, filtered water, and stable warmth. Now reclassified as Goeppertia by most taxonomists. Pet-safe by ASPCA standards.

Calathea (most species now placed in Goeppertia, family Marantaceae) comes from the tropical American rainforests, especially Brazil, growing under a thick canopy in filtered light and high humidity on the forest floor.

A compact, clump-forming evergreen perennial that is demanding on humidity and water quality rather than fast-growing. ASPCA classifies all Calathea/Goeppertia species as non-toxic to cats and dogs, making it a pet-safe option.

Cold limit: USDA 11-12 (indoor-only) · RHS H1b (18-24°C)

Sources: aspca.org, en.wikipedia.org, en.wikipedia.org

What calathea's hardiness rating actually means

Calathea 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 H1b means: Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season. On the US scale that maps to USDA 11-12 (indoor-only) — 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 10 °C (sustained cold below this is damaging). Calathea has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for calathea as it gets too cold:

Below about about 10 °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 calathea go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 10 °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 calathea can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Calathea hardiness — frequently asked questions

Is calathea cold hardy?

Calathea 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. Calathea can only live outside year-round in genuinely frost-free climates (roughly USDA 11-12 (indoor-only)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature calathea can survive?

Minimum survivable temperature is roughly about 10 °C (sustained cold below this is damaging). Calathea has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is calathea?

Calathea is rated USDA 11-12 (indoor-only) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can calathea survive winter outside?

It can holiday outdoors in summer once nights are reliably above 10 °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 calathea below its minimum temperature?

Below about about 10 °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.