Cold hardiness & minimum temperature

Is Spider Brake Fern (Pteris multifida)cold hardy? Hardiness zone & min temp

Also called Spider Brake Fern, Huguenot Fern.

More about spider brake fern

About Spider Brake Fern

Pteris multifida · also called Spider Brake Fern, Huguenot Fern · houseplant

The spider brake fern is a hardy, adaptable brake fern from East Asia with long, narrow, spidery pinnae that give it an airy, finger-like look. Tolerant of cooler rooms and lower light than many ferns, and naturalised on old walls in mild climates, it is among the toughest brakes for the home, wanting steady moisture, decent humidity and protection from direct sun.

Cold limit: USDA 8-11 (hardy in mild gardens, indoor elsewhere) · RHS H3 (10-24°C)

Watch for — Cold damage: Though tolerant of cool rooms, hard frost blackens the fronds; in marginal climates protect or overwinter it under cover.

What spider brake fern's hardiness rating actually means

Spider Brake Fern is half-hardy (RHS H3). 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 H3 means: Half-hardy — comes through mild UK winters outside but is killed by a hard freeze. On the US scale that maps to USDA 8-11 (hardy in mild gardens, indoor elsewhere) — 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 to 1 °C — a light, short frost only. Spider Brake Fern shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for spider brake fern as it gets too cold:

Down to roughly about −5 to 1 °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 spider brake fern go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 8-11 (hardy in mild gardens, indoor elsewhere) 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 spider brake fern can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H3 figure above.

Frost protection for borderline spider brake fern

Spider Brake Fern 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.

Spider Brake Fern hardiness — frequently asked questions

Is spider brake fern cold hardy?

Spider Brake Fern is half-hardy (RHS H3). 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 8-11 (hardy in mild gardens, indoor elsewhere) (and sheltered UK gardens) spider brake fern can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature spider brake fern can survive?

Minimum survivable temperature is roughly about −5 to 1 °C — a light, short frost only. Spider Brake Fern shrugs off cold nights but a real, sustained freeze will kill it.

What hardiness zone is spider brake fern?

Spider Brake Fern is rated USDA 8-11 (hardy in mild gardens, indoor elsewhere) and RHS H3 — Half-hardy — comes through mild UK winters outside but is killed by a hard freeze.

Can spider brake fern survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 8-11 (hardy in mild gardens, indoor elsewhere) 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 spider brake fern 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.