Cold hardiness & minimum temperature

Is Caladium (Caladium bicolor)cold hardy? Hardiness zone & min temp

Also called angel wings, elephant ear (small), heart of Jesus.

About Caladium

Caladium bicolor · also called angel wings, elephant ear (small) · tropical

Caladium is a tuberous tropical from Brazil with paper-thin heart-shaped leaves in pink, white, red, and green patterns. Grown indoors for a season or outdoors in summer beds; tubers go fully dormant in winter. Toxic to pets due to insoluble calcium oxalates.

Caladium bicolor, a tuberous tropical perennial native to forests of South and Central America that naturally experience pronounced wet and dry seasons.

Grows from a tuber and undergoes obligate seasonal dormancy: leaves die back, then in zones 8 and colder lift the tubers, dry them a week, and store in sphagnum at ~55–60°F for up to five months before replanting. Fancy-leaf types carry large heart-shaped leaves on 12–30 in petioles. All parts are poisonous if ingested.

Cold limit: USDA 9-11 (lifted as tubers elsewhere) · RHS H1b (21-29°C)

Watch for — No regrowth in spring: Cold storage or rotted tuber; store at 18-21°C, never below 13°C.

Sources: hort.extension.wisc.edu, missouribotanicalgarden.org, aspca.org

What caladium's hardiness rating actually means

Caladium 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 9-11 (lifted as tubers 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). Caladium has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Caladium hardiness — frequently asked questions

Is caladium cold hardy?

Caladium 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. Caladium can only live outside year-round in genuinely frost-free climates (roughly USDA 9-11 (lifted as tubers elsewhere)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature caladium can survive?

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

What hardiness zone is caladium?

Caladium is rated USDA 9-11 (lifted as tubers elsewhere) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can caladium 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 caladium 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.