Cold hardiness & minimum temperature

Is Colocasia Tea Cup (Colocasia esculenta 'Tea Cup')cold hardy? Hardiness zone & min temp

Also called Tea Cup alocasia, cup-leaf taro.

More about colocasia tea cup

About Colocasia Tea Cup

Colocasia esculenta 'Tea Cup' · also called Tea Cup alocasia, cup-leaf taro · tropical

Colocasia 'Tea Cup' (also sold as 'Tea Cup'/Coffee Cups) is a tall elephant ear whose leaves curl up at the edges to form cups that collect and tip out water. It wants heat, strong light and constantly moist, rich soil, reaching 1.2-1.8 m, and overwinters as a dormant tuber in cool climates.

Cold limit: USDA 7b-11 (relatively hardy; lift or mulch tubers in colder zones) · RHS H2 (18-30°C)

Watch for — Corm rot in winter: Cold, soggy soil during dormancy rots the tuber; cut back watering and keep stored corms cool but barely moist.

What colocasia tea cup's hardiness rating actually means

Colocasia Tea Cup 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 7b-11 (relatively hardy; lift or mulch tubers in colder zones) — 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. Colocasia Tea Cup shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for colocasia tea cup 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 colocasia tea cup go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 7b-11 (relatively hardy; lift or mulch tubers in colder zones) 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 colocasia tea cup 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 colocasia tea cup

Colocasia Tea Cup 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.

Colocasia Tea Cup hardiness — frequently asked questions

Is colocasia tea cup cold hardy?

Colocasia Tea Cup 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 7b-11 (relatively hardy; lift or mulch tubers in colder zones) (and sheltered UK gardens) colocasia tea cup can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature colocasia tea cup can survive?

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

What hardiness zone is colocasia tea cup?

Colocasia Tea Cup is rated USDA 7b-11 (relatively hardy; lift or mulch tubers in colder zones) and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can colocasia tea cup survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 7b-11 (relatively hardy; lift or mulch tubers in colder zones) 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 colocasia tea cup 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.