Cold hardiness & minimum temperature

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

Also called yellow foxglove, large yellow foxglove.

More about yellow foxglove

About Yellow Foxglove

Digitalis grandiflora · also called yellow foxglove, large yellow foxglove · flowering

Yellow foxglove is a hardy, often short-lived perennial bearing one-sided spires of soft primrose-yellow tubular flowers netted brown inside, in early to midsummer. Unlike the common biennial foxglove it returns year on year, thriving in part shade and humus-rich, moist but well-drained soil. All parts are toxic, containing heart-affecting cardiac glycosides.

Cold limit: USDA 3-8 (cold-hardy perennial) · RHS H7 (-34 to 24°C)

Watch for — Crown rot in wet winters: Waterlogged soil rots the crown over winter. Ensure good drainage, avoid heavy clay, and mulch rather than leave bare wet soil around the base.

What yellow foxglove's hardiness rating actually means

Yes — yellow foxglove is genuinely cold hardy. Rated RHS H7 and USDA 3-8 (cold-hardy perennial), 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 3-8 (cold-hardy perennial) — 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. Yellow Foxglove is built for winter — once established it takes hard frost and snow in its stride.

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

Plant it out within USDA 3-8 (cold-hardy perennial) 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 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.

Yellow Foxglove hardiness — frequently asked questions

Is yellow foxglove cold hardy?

Yes — yellow foxglove is genuinely cold hardy. Rated RHS H7 and USDA 3-8 (cold-hardy perennial), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Yellow Foxglove is hardy across USDA 3-8 (cold-hardy perennial); 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 yellow foxglove can survive?

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

What hardiness zone is yellow foxglove?

Yellow Foxglove is rated USDA 3-8 (cold-hardy perennial) and RHS H7 — Hardy in the severest European continental winters.

Can yellow foxglove survive winter outside?

Plant it out within USDA 3-8 (cold-hardy perennial) 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 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.