Cold hardiness & minimum temperature

Is Polypodium cambricum (Polypodium cambricum)cold hardy? Hardiness zone & min temp

Also called Southern Polypody, Welsh Polypody, Limestone Polypody.

More about polypodium cambricum

About Polypodium cambricum

Polypodium cambricum · also called Southern Polypody, Welsh Polypody · flowering

Polypodium cambricum is a winter-green European polypody fern of limestone rocks, walls and old hedgebanks. Its leathery, triangular fronds emerge in late summer and stay fresh through winter, then die back in summer. Lime-loving and drought-tolerant once established, it thrives in shady crevices and makes an easy, low-maintenance evergreen ground cover.

Cold limit: USDA 6-9 · RHS H5 (0-22°C)

What polypodium cambricum's hardiness rating actually means

Yes — polypodium cambricum is genuinely cold hardy. Rated RHS H5 and USDA 6-9, 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 6-9 — 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. Polypodium cambricum is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for polypodium cambricum 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 polypodium cambricum go outside or overwinter — and where?

Plant it out within USDA 6-9 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 polypodium cambricum can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Polypodium cambricum hardiness — frequently asked questions

Is polypodium cambricum cold hardy?

Yes — polypodium cambricum is genuinely cold hardy. Rated RHS H5 and USDA 6-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Polypodium cambricum is hardy across USDA 6-9; 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 polypodium cambricum can survive?

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

What hardiness zone is polypodium cambricum?

Polypodium cambricum is rated USDA 6-9 and RHS H5 — Hardy in most of the UK and in cold winters.

Can polypodium cambricum survive winter outside?

Plant it out within USDA 6-9 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 polypodium cambricum 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.