Cold hardiness & minimum temperature

Is Silver lace fern (Pteris ensiformis 'Evergemiensis')cold hardy? Hardiness zone & min temp

Also called silver lace fern, silver brake fern, slender brake fern, Victorian table fern, sword brake fern.

More about silver lace fern

About Silver lace fern

Pteris ensiformis 'Evergemiensis' · also called silver lace fern, silver brake fern · houseplant

Silver lace fern is a compact tropical brake fern prized for fronds striped with silvery-white centres. Indoors it wants bright indirect light, constantly moist humus-rich soil, and high humidity, and it has zero tolerance for drying out. The ASPCA lists Pteris ferns as non-toxic to cats and dogs, making it a pet-safe choice.

Cold limit: USDA 10-12 (indoor-only in most US and UK homes; RHS H1b, minimum ~13°C/55°F) (18-26°C)

Watch for — Sudden frond collapse or browning in winter: Cold draughts or temperatures below ~13°C/55°F; keep it away from cold windows, doors, and unheated rooms.

What silver lace fern's hardiness rating actually means

Silver lace 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 10-12 (indoor-only in most US and UK homes; RHS H1b, minimum ~13°C/55°F) — 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). Silver lace fern has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Silver lace fern hardiness — frequently asked questions

Is silver lace fern cold hardy?

Silver lace 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. Silver lace fern can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (indoor-only in most US and UK homes; RHS H1b, minimum ~13°C/55°F)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature silver lace fern can survive?

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

What hardiness zone is silver lace fern?

Silver lace fern is rated USDA 10-12 (indoor-only in most US and UK homes; RHS H1b, minimum ~13°C/55°F) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can silver lace 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 silver lace 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.