Cold hardiness & minimum temperature

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

Also called Welsh Polypody Crest.

More about polypodium cambricum 'cambricum'

About Polypodium cambricum 'Cambricum'

Polypodium cambricum 'Cambricum' · also called Welsh Polypody Crest · flowering

Polypodium cambricum 'Cambricum' is a historic, finely divided cultivar of the Welsh polypody, grown for its lacy, deeply cut sterile fronds. Winter-green and lime-loving like the species, it brings ornamental texture to shaded walls and rockeries. It rarely produces spores, so it is increased by rhizome division to keep the cultivar true.

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

What polypodium cambricum 'cambricum''s hardiness rating actually means

Yes — polypodium cambricum '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 'Cambricum' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for polypodium cambricum '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 '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 '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 'Cambricum' hardiness — frequently asked questions

Is polypodium cambricum 'cambricum' cold hardy?

Yes — polypodium cambricum '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 '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 'cambricum' can survive?

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

What hardiness zone is polypodium cambricum 'cambricum'?

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

Can polypodium cambricum '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 '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.