Cold hardiness & minimum temperature

Is Alpine Liverwort (Erinus alpinus)cold hardy? Hardiness zone & min temp

Also called Alpine liverwort, Fairy foxglove, Alpine balsam, Liver balsam.

More about alpine liverwort

About Alpine Liverwort

Erinus alpinus · also called Alpine liverwort, Fairy foxglove · flowering

Erinus alpinus is a semi-evergreen, rosette-forming alpine perennial native to mountain regions of southwestern Europe and North Africa, from the Pyrenees to the Atlas Mountains, where it colonises rock faces, old walls, and scree. Despite its common name 'fairy foxglove', it belongs to the family Plantaginaceae, not Scrophulariaceae. It produces abundant small, star-shaped flowers in pink, purple, or white over the rosettes from late spring to early summer and self-seeds freely into crevices. The plant is short-lived, typically three to five years, but perpetuates itself readily from seed. Erinus alpinus is not listed by the ASPCA as toxic to cats or dogs.

Cold limit: USDA 4-7 · RHS H6 (-20 to 25°C)

Watch for — Collar rot: Caused by waterlogged soil at the base of the rosette, particularly after wet winters; ensure very sharp drainage and avoid watering the crown directly.

What alpine liverwort's hardiness rating actually means

Yes — alpine liverwort is genuinely cold hardy. Rated RHS H6 and USDA 4-7, 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 4-7 — 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 −20 to −15 °C. Alpine Liverwort is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for alpine liverwort 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 alpine liverwort go outside or overwinter — and where?

Plant it out within USDA 4-7 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 alpine liverwort can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Alpine Liverwort hardiness — frequently asked questions

Is alpine liverwort cold hardy?

Yes — alpine liverwort is genuinely cold hardy. Rated RHS H6 and USDA 4-7, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Alpine Liverwort is hardy across USDA 4-7; 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 alpine liverwort can survive?

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

What hardiness zone is alpine liverwort?

Alpine Liverwort is rated USDA 4-7 and RHS H6 — Hardy throughout the UK and northern Europe.

Can alpine liverwort survive winter outside?

Plant it out within USDA 4-7 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 alpine liverwort 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.