Cold hardiness & minimum temperature

Is Clinton's Wood Fern (Dryopteris clintoniana)cold hardy? Hardiness zone & min temp

Also called Clinton's Wood Fern, Clinton's Fern, Clinton's Shield Fern.

More about clinton's wood fern

About Clinton's Wood Fern

Dryopteris clintoniana · also called Clinton's Wood Fern, Clinton's Fern · houseplant

A tall, stately semi-evergreen fern of moist north-eastern North American woodlands and swamps, believed to be a fertile hybrid between crested wood fern (D. cristata) and Goldie's fern (D. goldiana), inheriting the robust stature of the latter. It produces arching, lance-shaped, dark green fronds up to 100 cm long with pinnae that are slightly twisted on the rachis, creating a lacy, open texture. Dimorphic in frond form, with larger erect fertile fronds and smaller prostrate sterile ones that remain green through mild winters. Dryopteris clintoniana is not individually listed by the ASPCA and should be treated as mildly-toxic for pets as a precaution.

Cold limit: USDA 3-7 · RHS H5 (-30°C to 22°C)

What clinton's wood fern's hardiness rating actually means

Yes — clinton's wood fern is genuinely cold hardy. Rated RHS H5 and USDA 3-7, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H5 means: Hardy in most of the UK and in cold winters. On the US scale that maps to USDA 3-7 — 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 −15 to −10 °C. Clinton's Wood Fern is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for clinton's wood fern as it gets too cold:

It tolerates winter lows to about −15 to −10 °C once established.
Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root.
First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.

Can clinton's wood fern go outside or overwinter — and where?

Plant it out within USDA 3-7 and it overwinters with little or no help.
It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy.
The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

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 clinton's wood fern can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Clinton's Wood Fern hardiness — frequently asked questions

Is clinton's wood fern cold hardy?

Yes — clinton's wood fern is genuinely cold hardy. Rated RHS H5 and USDA 3-7, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Clinton's Wood Fern is hardy across USDA 3-7; it belongs in the ground or a frost-proof container, not on a windowsill, and many types actively need a cold winter to perform.

What is the minimum temperature clinton's wood fern can survive?

Minimum survivable temperature is roughly about −15 to −10 °C. Clinton's Wood Fern is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is clinton's wood fern?

Clinton's Wood Fern is rated USDA 3-7 and RHS H5 — Hardy in most of the UK and in cold winters.

Can clinton's wood fern survive winter outside?

Plant it out within USDA 3-7 and it overwinters with little or no help. It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy. The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

What happens to clinton's wood fern below its minimum temperature?

It tolerates winter lows to about −15 to −10 °C once established. Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root. First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.