Cold hardiness & minimum temperature

Is Large Yellow Foxglove (Digitalis grandiflora)cold hardy? Hardiness zone & min temp

Also called Yellow foxglove, Large-flowered foxglove, Perennial foxglove.

More about large yellow foxglove

About Large Yellow Foxglove

Digitalis grandiflora · also called Yellow foxglove, Large-flowered foxglove · flowering

A true perennial foxglove bearing elegant spikes of pale creamy-yellow, brown-veined tubular flowers from early to midsummer. More refined and less towering than D. purpurea. Thrives in woodland-edge planting and shaded borders. Long-lived for a foxglove. Highly toxic — all parts contain cardiac glycosides dangerous to pets and people.

Cold limit: USDA 3–9 · RHS H7 (−20–28°C)

Watch for — Crown rot in wet winters: Moist but well-drained conditions are essential; standing water kills the crown.

What large yellow foxglove's hardiness rating actually means

Yes — large yellow foxglove is genuinely cold hardy. Rated RHS H7 and USDA 3–9, it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H7 means: Hardy in the severest European continental winters. On the US scale that maps to USDA 3–9 — 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 below about −20 °C. Large Yellow Foxglove is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for large yellow foxglove as it gets too cold:

It tolerates winter lows to about −20 °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 large yellow foxglove go outside or overwinter — and where?

Plant it out within USDA 3–9 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 large yellow foxglove can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Large Yellow Foxglove hardiness — frequently asked questions

Is large yellow foxglove cold hardy?

Yes — large yellow foxglove is genuinely cold hardy. Rated RHS H7 and USDA 3–9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Large Yellow Foxglove is hardy across USDA 3–9; 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 large yellow foxglove can survive?

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

What hardiness zone is large yellow foxglove?

Large Yellow Foxglove is rated USDA 3–9 and RHS H7 — Hardy in the severest European continental winters.

Can large yellow foxglove survive winter outside?

Plant it out within USDA 3–9 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 large yellow foxglove below its minimum temperature?

It tolerates winter lows to about −20 °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.