Cold hardiness & minimum temperature

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

Also called Moonlight caladium.

More about caladium moonlight

About Caladium Moonlight

Caladium 'Moonlight' · also called Moonlight caladium · tropical

Moonlight is a fancy-leaf caladium with softly ruffled, almost entirely white heart-shaped leaves traced by delicate green veining, glowing in shaded settings. Grown from tubers, it brightens dim corners of the garden or home through the warm season before going dormant. It loves warmth, steady moisture and humidity, and shelters from harsh sun and cold.

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

Watch for — Tuber rot: Cold or wet soil during dormancy or early planting rots tubers. Keep them warm and barely moist; plant only into warm soil.

What caladium moonlight's hardiness rating actually means

Caladium Moonlight 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 Moonlight has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Caladium Moonlight hardiness — frequently asked questions

Is caladium moonlight cold hardy?

Caladium Moonlight 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 Moonlight 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 moonlight can survive?

What hardiness zone is caladium moonlight?

Caladium Moonlight 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 moonlight 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 moonlight 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.