Cold hardiness & minimum temperature

Is Foxglove (Digitalis purpurea)cold hardy? Hardiness zone & min temp

Also called Foxglove, Common Foxglove, Lady's Glove, Fairy Fingers.

More about foxglove

About Foxglove

Digitalis purpurea · also called Foxglove, Common Foxglove · flowering

Digitalis purpurea is a tall biennial or short-lived perennial native to western and central Europe, including the UK, where it is a quintessential woodland-edge and cottage-garden plant. In its first year it forms a large flat rosette of velvety leaves; in its second it throws up a commanding spike of tubular, spotted flowers beloved by bumblebees. The most important care fact is to site it in partial shade with moisture-retentive, humus-rich soil, and to allow self-seeding for a continuous display. Every part of this plant is highly toxic to pets and humans.

Cold limit: USDA 4-9 · RHS H6 (-15 to 25°C)

Watch for — Crown rot / failure to overwinter: Wet, cold soil around the crown in winter kills the rosette, especially on heavy clay — plant in well-drained positions and avoid autumn mulching that contacts the crown.

What foxglove's hardiness rating actually means

Yes — foxglove is genuinely cold hardy. Rated RHS H6 and USDA 4-9, 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 4-9 — 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 −20 to −15 °C. Foxglove is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for foxglove 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 foxglove go outside or overwinter — and where?

Plant it out within USDA 4-9 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 foxglove can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Foxglove hardiness — frequently asked questions

Is foxglove cold hardy?

Yes — foxglove is genuinely cold hardy. Rated RHS H6 and USDA 4-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Foxglove is hardy across USDA 4-9; 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 foxglove can survive?

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

What hardiness zone is foxglove?

Foxglove is rated USDA 4-9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can foxglove survive winter outside?

Plant it out within USDA 4-9 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 foxglove 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.