Cold hardiness & minimum temperature

Is Tiger Fern (Nephrolepis exaltata 'Tiger Fern')cold hardy? Hardiness zone & min temp

Also called Variegated Boston fern, Tiger stripe fern.

More about tiger fern

About Tiger Fern

Nephrolepis exaltata 'Tiger Fern' · also called Variegated Boston fern, Tiger stripe fern · houseplant

The Tiger Fern is a variegated Boston fern prized for fronds randomly streaked and banded in gold and lime against green. Variegation is unstable, so it needs bright indirect light to hold its markings. Like all Boston ferns it wants moist soil, high humidity and warmth, and is fully pet-safe.

Cold limit: USDA 9-11 outdoors; grown as a houseplant in most US homes · RHS H1c (16-24°C)

Watch for — Yellowing fronds: Overwatering, poor drainage or cold draughts. Check the pot drains freely, ease off water, and keep it away from vents and cold glass.

What tiger fern's hardiness rating actually means

Tiger Fern 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 H1c means: Warm-temperate — can summer outdoors but must come in well before the first frost. On the US scale that maps to USDA 9-11 outdoors; grown as a houseplant in most US homes — 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 5 °C (and never frost). Tiger Fern has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for tiger fern as it gets too cold:

Below about about 5 °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 tiger fern go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 5 °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 tiger fern can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Tiger Fern hardiness — frequently asked questions

Is tiger fern cold hardy?

Tiger Fern 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. Tiger Fern can only live outside year-round in genuinely frost-free climates (roughly USDA 9-11 outdoors; grown as a houseplant in most US homes); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature tiger fern can survive?

Minimum survivable temperature is roughly about 5 °C (and never frost). Tiger Fern has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is tiger fern?

Tiger Fern is rated USDA 9-11 outdoors; grown as a houseplant in most US homes and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can tiger fern survive winter outside?

It can holiday outdoors in summer once nights are reliably above 5 °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 tiger fern below its minimum temperature?

Below about about 5 °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.