Cold hardiness & minimum temperature

Is Clarke's Cranesbill (Geranium clarkei)cold hardy? Hardiness zone & min temp

Also called Clarke's cranesbill, Kashmir cranesbill.

More about clarke's cranesbill

About Clarke's Cranesbill

Geranium clarkei · also called Clarke's cranesbill, Kashmir cranesbill · flowering

Geranium clarkei is a rhizomatous hardy perennial native to the alpine meadows of Kashmir and the western Himalayas, where it grows in moist, grassy habitats. It forms spreading clumps of finely divided, deeply cut foliage and bears large, upward-facing flowers in white or soft lilac with pale purple veining from early to midsummer. The most important care tip is to divide clumps every 3-4 years in spring to maintain vigour, as established mats can become congested. Considered non-toxic to cats and dogs.

Cold limit: USDA 4-8 · RHS H6 (-20 to 24°C)

What clarke's cranesbill's hardiness rating actually means

Yes — clarke's cranesbill is genuinely cold hardy. Rated RHS H6 and USDA 4-8, 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 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 about −20 to −15 °C. Clarke's Cranesbill is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for clarke's 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 clarke's cranesbill 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 clarke's cranesbill can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Clarke's Cranesbill hardiness — frequently asked questions

Is clarke's cranesbill cold hardy?

Yes — clarke's cranesbill is genuinely cold hardy. Rated RHS H6 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Clarke's Cranesbill 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 clarke's cranesbill can survive?

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

What hardiness zone is clarke's cranesbill?

Clarke's Cranesbill is rated USDA 4-8 and RHS H6 — Hardy throughout the UK and northern Europe.

Can clarke's cranesbill 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 clarke's 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.