Cold hardiness & minimum temperature

Is Afzel's Nephthytis (Nephthytis afzelii)cold hardy? Hardiness zone & min temp

Also called Afzelius Nephthytis, West African Arrow Aroid.

More about afzel's nephthytis

About Afzel's Nephthytis

Nephthytis afzelii · also called Afzelius Nephthytis, West African Arrow Aroid · tropical

Nephthytis afzelii is a compact, low-growing aroid from West African tropical forests, forming clumps of arrow-shaped leaves on slender petioles. Unlike Syngonium (which is often mislabelled as Nephthytis commercially), true Nephthytis species are rare in cultivation. All parts contain calcium oxalate crystals and are toxic to pets and people.

Cold limit: USDA 11-12 (indoor-only) · RHS H1a (18-28°C)

What afzel's nephthytis's hardiness rating actually means

Afzel's Nephthytis 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 H1a means: Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever. On the US scale that maps to USDA 11-12 (indoor-only) — 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 above about 15 °C (warm, never cold). Afzel's Nephthytis has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for afzel's nephthytis as it gets too cold:

Below about above about 15 °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 afzel's nephthytis go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above above 15 °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 afzel's nephthytis can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1a figure above.

Afzel's Nephthytis hardiness — frequently asked questions

Is afzel's nephthytis cold hardy?

Afzel's Nephthytis 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. Afzel's Nephthytis can only live outside year-round in genuinely frost-free climates (roughly USDA 11-12 (indoor-only)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature afzel's nephthytis can survive?

Minimum survivable temperature is roughly above about 15 °C (warm, never cold). Afzel's Nephthytis has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is afzel's nephthytis?

Afzel's Nephthytis is rated USDA 11-12 (indoor-only) and RHS H1a — Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever.

Can afzel's nephthytis survive winter outside?

It can holiday outdoors in summer once nights are reliably above above 15 °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 afzel's nephthytis below its minimum temperature?

Below about above about 15 °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.