Cold hardiness & minimum temperature

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

Also called Candidum caladium, white caladium.

More about caladium candidum

About Caladium Candidum

Caladium bicolor 'Candidum' · also called Candidum caladium, white caladium · tropical

Candidum is a heritage fancy-leaf caladium with large, translucent white heart-shaped leaves laced by a fine network of green veins. One of the oldest and most popular white cultivars, it brings a cool, luminous glow to shady borders and containers. Tuber-grown and warmth-loving, it flushes through summer then goes dormant in cool conditions.

Cold limit: USDA 9-11 outdoors (lift tubers in cooler zones; indoor elsewhere) · RHS H1b (21-29°C)

Watch for — Yellowing and dieback: Often the natural onset of dormancy as days shorten or temperatures fall. Reduce water and store the tuber warm and dry.

What caladium candidum's hardiness rating actually means

Caladium Candidum 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 outdoors (lift tubers in cooler zones; indoor 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 Candidum has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Caladium Candidum hardiness — frequently asked questions

Is caladium candidum cold hardy?

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

What is the minimum temperature caladium candidum can survive?

What hardiness zone is caladium candidum?

Caladium Candidum is rated USDA 9-11 outdoors (lift tubers in cooler zones; indoor elsewhere) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can caladium candidum 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 candidum 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.