Cold hardiness & minimum temperature

Is Foxglove beardtongue (Penstemon digitalis)cold hardy? Hardiness zone & min temp

Also called Foxglove beardtongue, Talus slope penstemon, White beardtongue.

More about foxglove beardtongue

About Foxglove beardtongue

Penstemon digitalis · also called Foxglove beardtongue, Talus slope penstemon · flowering

A native North American perennial producing tall spikes of white to pale-lavender tubular flowers in early summer, beloved by hummingbirds and bees. More tolerant of clay and moisture than most penstemons. The cultivar 'Husker Red' is widely grown for its burgundy foliage. Largely deer-resistant and very cold-hardy.

Cold limit: USDA 3–8 · RHS H7 (-35 to 30°C)

Watch for — Crown rot in wet winter soils: Prolonged waterlogging, especially in cold winters, can cause crown and root rot. Improve drainage before planting and avoid mulching directly over the crown. Raised beds or gritty soil amendments help in heavier soils.

What foxglove beardtongue's hardiness rating actually means

Yes — foxglove beardtongue is genuinely cold hardy. Rated RHS H7 and USDA 3–8, 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 — 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. Foxglove beardtongue is built for winter — once established it takes hard frost and snow in its stride.

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

Plant it out within USDA 3–8 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 beardtongue can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Foxglove beardtongue hardiness — frequently asked questions

Is foxglove beardtongue cold hardy?

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

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

What hardiness zone is foxglove beardtongue?

Foxglove beardtongue is rated USDA 3–8 and RHS H7 — Hardy in the severest European continental winters.

Can foxglove beardtongue survive winter outside?

Plant it out within USDA 3–8 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 beardtongue 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.