Cold hardiness & minimum temperature

Is Cliff Holly Fern (Cyrtomium fortunei var. clivicola)cold hardy? Hardiness zone & min temp

Also called Cliff Holly Fern, Arching Japanese Holly Fern, Spreading Japanese Holly Fern.

More about cliff holly fern

About Cliff Holly Fern

Cyrtomium fortunei var. clivicola · also called Cliff Holly Fern, Arching Japanese Holly Fern · houseplant

A compact, arching variety of Fortune's holly fern with leathery, holly-like pinnae held on nearly horizontal fronds. More spreading in habit than the species, it is remarkably drought tolerant once established and will thrive in deep shade where most ferns struggle. An excellent, low-maintenance houseplant suited to beginners.

Cold limit: USDA 6–10 · RHS H5 (5–22°C)

What cliff holly fern's hardiness rating actually means

Yes — cliff holly fern is genuinely cold hardy. Rated RHS H5 and USDA 6–10, 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 6–10 — 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. Cliff Holly Fern is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for cliff holly 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 cliff holly fern go outside or overwinter — and where?

Plant it out within USDA 6–10 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 cliff holly fern can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Cliff Holly Fern hardiness — frequently asked questions

Is cliff holly fern cold hardy?

Yes — cliff holly fern is genuinely cold hardy. Rated RHS H5 and USDA 6–10, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Cliff Holly Fern is hardy across USDA 6–10; 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 cliff holly fern can survive?

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

What hardiness zone is cliff holly fern?

Cliff Holly Fern is rated USDA 6–10 and RHS H5 — Hardy in most of the UK and in cold winters.

Can cliff holly fern survive winter outside?

Plant it out within USDA 6–10 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 cliff holly 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.