Cold hardiness & minimum temperature

Is Giant Taro (Alocasia macrorrhizos)cold hardy? Hardiness zone & min temp

Also called Giant Elephant Ear, Upright Elephant Ear.

More about giant taro

About Giant Taro

Alocasia macrorrhizos · also called Giant Elephant Ear, Upright Elephant Ear · tropical

Giant Taro is a massive upright Alocasia with glossy, arrow-shaped leaves held skyward on stout stems, reaching several metres in the tropics. It makes a bold architectural statement indoors and out. A fast, hungry, thirsty aroid, it loves warmth, rich soil and high humidity, and demands far more water than most houseplant Alocasias.

Cold limit: USDA 9b-11 (lift or mulch the rhizome below zone 9) · RHS H1b (18-30°C)

Watch for — Drooping or wilting: Most often underwatering in this thirsty bog plant, or sudden cold; keep the soil evenly moist and warm, and it usually perks back up.

What giant taro's hardiness rating actually means

Giant Taro 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 9b-11 (lift or mulch the rhizome below zone 9) — 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). Giant Taro has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Giant Taro hardiness — frequently asked questions

Is giant taro cold hardy?

Giant Taro 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. Giant Taro can only live outside year-round in genuinely frost-free climates (roughly USDA 9b-11 (lift or mulch the rhizome below zone 9)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature giant taro can survive?

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

What hardiness zone is giant taro?

Giant Taro is rated USDA 9b-11 (lift or mulch the rhizome below zone 9) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can giant taro 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 giant taro 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.