Cold hardiness & minimum temperature

Is Staghorn fern (Platycerium bifurcatum)cold hardy? Hardiness zone & min temp

Also called elkhorn fern, common staghorn.

About Staghorn fern

Platycerium bifurcatum · also called elkhorn fern, common staghorn · houseplant

Staghorn fern is an epiphytic fern from Australia and New Guinea that grows on tree branches and is most often mounted to a board indoors. It has shield-like basal fronds and antler-shaped fertile fronds. Pet-safe by ASPCA standards.

Platycerium bifurcatum is an epiphytic fern of the polypod family native primarily to tropical Africa, Australia and Southeast Asia, growing anchored to tree trunks and branches rather than in soil.

A long-lived tender epiphyte (minimum around 10C, USDA zones 9-12) that can form large clumps and produce pups (offsets) from the rhizome; holds the RHS Award of Garden Merit.

Cold limit: USDA 9-12 · RHS H1c (16-27°C)

Sources: rhs.org.uk, missouribotanicalgarden.org, hort.extension.wisc.edu

What staghorn fern's hardiness rating actually means

Staghorn 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 9-12 — 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). Staghorn fern has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for staghorn 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 staghorn 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 staghorn fern can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Staghorn fern hardiness — frequently asked questions

Is staghorn fern cold hardy?

Staghorn 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. Staghorn fern can only live outside year-round in genuinely frost-free climates (roughly USDA 9-12); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature staghorn fern can survive?

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

What hardiness zone is staghorn fern?

Staghorn fern is rated USDA 9-12 and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can staghorn 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 staghorn 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.