Cold hardiness & minimum temperature

Is Rattlesnake plant (Goeppertia insignis)cold hardy? Hardiness zone & min temp

Also called Rattlesnake plant, Rattlesnake calathea, Calathea lancifolia, Calathea insignis, Prayer plant.

More about rattlesnake plant

About Rattlesnake plant

Goeppertia insignis · also called Rattlesnake plant, Rattlesnake calathea · tropical

The rattlesnake plant (Goeppertia insignis, long sold as Calathea lancifolia) is a Brazilian rainforest perennial grown for wavy, lance-shaped leaves marbled with dark spots above a purple underside. Its defining need is steady warmth and high humidity with consistently moist soil; the foliage browns quickly in dry air or hard tap water.

Cold limit: 18-24°C

Watch for — Curling or limp, fading leaves: Tightly curled leaves usually signal underwatering or dry air, while yellowing and limpness point to overwatering or cold draughts. Keep compost evenly moist and away from radiators and cold windows.

What rattlesnake plant's hardiness rating actually means

Rattlesnake plant 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 not formally rated (treat as tender) — 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). Rattlesnake plant has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Rattlesnake plant hardiness — frequently asked questions

Is rattlesnake plant cold hardy?

Rattlesnake plant 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. Rattlesnake plant can only live outside year-round in genuinely frost-free climates (roughly USDA not formally rated (treat as tender)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature rattlesnake plant can survive?

What hardiness zone is rattlesnake plant?

Rattlesnake plant is rated USDA not formally rated (treat as tender) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can rattlesnake plant 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 rattlesnake plant 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.