Cold hardiness & minimum temperature

Is Elephant ear (Colocasia esculenta)cold hardy? Hardiness zone & min temp

Also called taro, cocoyam, dasheen.

About Elephant ear

Colocasia esculenta · also called taro, cocoyam · tropical

Elephant ear is a dramatic tropical from Asia and the Pacific grown for its huge heart-shaped leaves. Colocasia and Alocasia are often confused; both are called elephant ear. Colocasia leaves point down, Alocasia leaves point up. Toxic to pets.

Colocasia esculenta (elephant ear / taro) is native to tropical southern Asia and the Pacific, a wetland marsh plant grown for thousands of years from a starchy corm; it is adapted to constant heat and abundant water.

A bold perennial herb to about 4-6 ft with very large arrow-shaped leaves; ASPCA lists it as toxic to dogs, cats and horses (insoluble calcium oxalates), causing intense oral pain, drooling, swelling and difficulty swallowing if chewed.

Cold limit: USDA 8-11 outdoors; indoor elsewhere · RHS H2-H3 (lift tubers in cold winters) (18-29°C)

Sources: aspca.org, hort.extension.wisc.edu, plants.ces.ncsu.edu

What elephant ear's hardiness rating actually means

Elephant ear is half-hardy (RHS H2). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Its RHS rating of H2 means: Tender — survives a frost-free greenhouse or a very mild, sheltered spot. On the US scale that maps to USDA 8-11 outdoors; 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 1 to 5 °C — tolerates cold but no real frost. Elephant ear shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for elephant ear as it gets too cold:

Down to roughly about 1 to 5 °C it copes, especially if dry and sheltered.
A sustained hard frost collapses the top growth; whether it returns depends on whether the roots, crown or tubers froze.
Wet cold is far more lethal than dry cold for this plant — soggy, frozen soil is the usual killer.

Can elephant ear go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 8-11 outdoors; indoor elsewhere or a frost-free UK microclimate.
In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter.
A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

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 elephant ear can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H2 figure above.

Frost protection for borderline elephant ear

Elephant ear is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost.
Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse.
Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones.
Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.

Elephant ear hardiness — frequently asked questions

Is elephant ear cold hardy?

Elephant ear is half-hardy (RHS H2). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Borderline outdoors. In its mild end of USDA 8-11 outdoors; indoor elsewhere (and sheltered UK gardens) elephant ear can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature elephant ear can survive?

Minimum survivable temperature is roughly about 1 to 5 °C — tolerates cold but no real frost. Elephant ear shrugs off cold nights but a real, sustained freeze will kill it.

What hardiness zone is elephant ear?

Elephant ear is rated USDA 8-11 outdoors; indoor elsewhere and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can elephant ear survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 8-11 outdoors; indoor elsewhere or a frost-free UK microclimate. In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter. A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

How do I protect elephant ear from frost?

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost. Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse. Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones. Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.