Cold hardiness & minimum temperature

Is Fittonia (Fittonia albivenis)cold hardy? Hardiness zone & min temp

Also called nerve plant, mosaic plant.

About Fittonia

Fittonia albivenis · also called nerve plant, mosaic plant · houseplant

Fittonia is a low-growing tropical from Peruvian rainforests, grown for its leaves veined in white, pink, or red. It is famously dramatic — it wilts flat the moment the soil dries — but recovers quickly when watered. Pet-safe by ASPCA standards.

The nerve plant, Fittonia albivenis, is native to the rainforests of Peru and the wider western Amazon basin (Colombia, Bolivia, Ecuador, northern Brazil), where it forms low, dense mats on the warm, shaded, perpetually humid forest floor.

A low (under ~15 cm) spreading tropical perennial that needs warmth and high humidity (commonly cited 50%+ and ideally higher); the ASPCA lists nerve plant as non-toxic to cats and dogs.

Cold limit: USDA 10-11 (indoor-only) · RHS H1b (18-26°C)

Sources: aspca.org, en.wikipedia.org, gardenerspath.com

What fittonia's hardiness rating actually means

Fittonia 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 10-11 (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 about 10 °C (sustained cold below this is damaging). Fittonia has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Fittonia hardiness — frequently asked questions

Is fittonia cold hardy?

Fittonia 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. Fittonia can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (indoor-only)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature fittonia can survive?

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

What hardiness zone is fittonia?

Fittonia is rated USDA 10-11 (indoor-only) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can fittonia 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 fittonia 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.