Cold hardiness & minimum temperature

Is Yellow Pimpernel (Lysimachia nemorum)cold hardy? Hardiness zone & min temp

Also called Yellow Pimpernel, Wood Pimpernel.

More about yellow pimpernel

About Yellow Pimpernel

Lysimachia nemorum · also called Yellow Pimpernel, Wood Pimpernel · flowering

Lysimachia nemorum is a low-growing, evergreen creeping perennial native to damp deciduous woodlands and shaded streamsides across the British Isles and western Europe. It thrives in moist, humus-rich soil in partial to deep shade — the key care point is that it needs consistent moisture and will not tolerate drying out. The bright star-shaped yellow flowers, about 8 mm across, appear from May to July. It likely contains saponins typical of the Primulaceae family and should be treated as mildly toxic to pets.

Cold limit: USDA 4-8 · RHS H7 (-25 to 22°C)

What yellow pimpernel's hardiness rating actually means

Yes — yellow pimpernel is genuinely cold hardy. Rated RHS H7 and USDA 4-8, 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 4-8 — 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. Yellow Pimpernel is built for winter — once established it takes hard frost and snow in its stride.

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

Plant it out within USDA 4-8 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 yellow pimpernel can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Yellow Pimpernel hardiness — frequently asked questions

Is yellow pimpernel cold hardy?

Yes — yellow pimpernel is genuinely cold hardy. Rated RHS H7 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Yellow Pimpernel is hardy across USDA 4-8; 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 yellow pimpernel can survive?

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

What hardiness zone is yellow pimpernel?

Yellow Pimpernel is rated USDA 4-8 and RHS H7 — Hardy in the severest European continental winters.

Can yellow pimpernel survive winter outside?

Plant it out within USDA 4-8 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 yellow pimpernel 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.