Cold hardiness & minimum temperature

Is Wood Fern 'The King' (Dryopteris affinis 'The King')cold hardy? Hardiness zone & min temp

Also called Golden-scaled male fern, King male fern.

More about wood fern 'the king'

About Wood Fern 'The King'

Dryopteris affinis 'The King' · also called Golden-scaled male fern, King male fern · houseplant

'The King' (often listed as 'Cristata The King') is a stately golden-scaled male fern with tall, upright fronds whose tips and pinnae are crested into tasselled crests. Semi-evergreen and very hardy, it forms a bold shuttlecock with golden-brown scaly stems. Like all Dryopteris it shares the genus's rhizome chemistry, so it is not a pet-safe fern.

Cold limit: USDA 4-8 (outdoor-hardy; indoors only as a cool-room or seasonal fern) · RHS H6 (10-22°C)

Watch for — Weather-tatty fronds in spring: Old semi-evergreen fronds get damaged over winter. Cut them to the crown in late winter before the new flush unfurls.

What wood fern 'the king''s hardiness rating actually means

Yes — wood fern 'the king' is genuinely cold hardy. Rated RHS H6 and USDA 4-8 (outdoor-hardy; indoors only as a cool-room or seasonal fern), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H6 means: Hardy throughout the UK and northern Europe. On the US scale that maps to USDA 4-8 (outdoor-hardy; indoors only as a cool-room or seasonal fern) — 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 −20 to −15 °C. Wood Fern 'The King' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for wood fern 'the king' as it gets too cold:

It tolerates winter lows to about −20 to −15 °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 wood fern 'the king' go outside or overwinter — and where?

Plant it out within USDA 4-8 (outdoor-hardy; indoors only as a cool-room or seasonal fern) 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 wood fern 'the king' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Wood Fern 'The King' hardiness — frequently asked questions

Is wood fern 'the king' cold hardy?

Yes — wood fern 'the king' is genuinely cold hardy. Rated RHS H6 and USDA 4-8 (outdoor-hardy; indoors only as a cool-room or seasonal fern), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Wood Fern 'The King' is hardy across USDA 4-8 (outdoor-hardy; indoors only as a cool-room or seasonal fern); 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 wood fern 'the king' can survive?

Minimum survivable temperature is roughly about −20 to −15 °C. Wood Fern 'The King' is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is wood fern 'the king'?

Wood Fern 'The King' is rated USDA 4-8 (outdoor-hardy; indoors only as a cool-room or seasonal fern) and RHS H6 — Hardy throughout the UK and northern Europe.

Can wood fern 'the king' survive winter outside?

Plant it out within USDA 4-8 (outdoor-hardy; indoors only as a cool-room or seasonal fern) 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 wood fern 'the king' below its minimum temperature?

It tolerates winter lows to about −20 to −15 °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.