Cold hardiness & minimum temperature

Is Shining Cranesbill (Geranium lucidum)cold hardy? Hardiness zone & min temp

Also called Shining Cranesbill, Shining Geranium.

More about shining cranesbill

About Shining Cranesbill

Geranium lucidum · also called Shining Cranesbill, Shining Geranium · flowering

Geranium lucidum is a dainty annual or biennial native to Europe, North Africa and western Asia, typically colonising limestone walls, rocky banks and hedgerows. It is distinctive for its glossy, red-tinged leaves and bright, brittle, fleshy stems that flush vivid crimson in autumn. It prefers well-drained, alkaline soils in sun or partial shade and is highly drought-tolerant. True Geranium cranesbills are not listed as toxic to pets by the ASPCA — this species is considered non-toxic to cats and dogs.

Cold limit: USDA 5-9 · RHS H6 (-20 to 25°C)

What shining cranesbill's hardiness rating actually means

Yes — shining cranesbill is genuinely cold hardy. Rated RHS H6 and USDA 5-9, 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 5-9 — 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. Shining Cranesbill is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for shining cranesbill 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 shining cranesbill go outside or overwinter — and where?

Plant it out within USDA 5-9 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 shining cranesbill can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Shining Cranesbill hardiness — frequently asked questions

Is shining cranesbill cold hardy?

Yes — shining cranesbill is genuinely cold hardy. Rated RHS H6 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Shining Cranesbill is hardy across USDA 5-9; 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 shining cranesbill can survive?

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

What hardiness zone is shining cranesbill?

Shining Cranesbill is rated USDA 5-9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can shining cranesbill survive winter outside?

Plant it out within USDA 5-9 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 shining cranesbill 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.