Cold hardiness & minimum temperature

Is Calathea Crotalifera (Goeppertia crotalifera)cold hardy? Hardiness zone & min temp

Also called rattlebox calathea, rattlesnake ginger, rattleweed.

More about calathea crotalifera

About Calathea Crotalifera

Goeppertia crotalifera · also called rattlebox calathea, rattlesnake ginger · tropical

Calathea crotalifera, the rattlesnake plant, is a large tropical grown as much for its bizarre, flattened yellow flower bracts that resemble a rattlesnake's tail as for its broad paddle leaves. A vigorous, clumping understorey species, it wants warmth, steady moisture and humidity. Outdoors in the tropics it towers; indoors it stays a bold, pet-safe statement plant.

Cold limit: USDA 10-12 (root-hardy in zone 10 with protection; houseplant elsewhere) · RHS H1b (18-29°C)

Watch for — Wilting and leaf collapse: Underwatering or cold draughts stress this thirsty plant. Keep the soil evenly moist and temperatures above 18°C.

What calathea crotalifera's hardiness rating actually means

Calathea Crotalifera 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 10-12 (root-hardy in zone 10 with protection; houseplant elsewhere) — 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 Crotalifera has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for calathea crotalifera 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 crotalifera 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 crotalifera can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Calathea Crotalifera hardiness — frequently asked questions

Is calathea crotalifera cold hardy?

Calathea Crotalifera 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 Crotalifera can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (root-hardy in zone 10 with protection; houseplant elsewhere)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature calathea crotalifera can survive?

What hardiness zone is calathea crotalifera?

Calathea Crotalifera is rated USDA 10-12 (root-hardy in zone 10 with protection; houseplant elsewhere) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can calathea crotalifera 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 crotalifera 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.