Cold hardiness & minimum temperature

Is Wallich's Cranesbill (Geranium wallichianum)cold hardy? Hardiness zone & min temp

Also called Wallich's cranesbill, Wallich geranium.

More about wallich's cranesbill

About Wallich's Cranesbill

Geranium wallichianum · also called Wallich's cranesbill, Wallich geranium · flowering

Geranium wallichianum is a scrambling, trailing hardy perennial from the Himalayas and Afghanistan, bearing large saucer-shaped flowers — typically violet-blue to magenta with a contrasting white eye — from midsummer right through to the first frosts. Unlike upright clump-forming cranesbills, it sprawls across neighbouring plants and the ground, making it excellent for weaving through shrubs or spilling over banks. The famous cultivar 'Buxton's Variety' carries rich blue flowers whose colour fades to pink in summer heat and returns to blue in cooler weather. Considered non-toxic to cats and dogs.

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

What wallich's cranesbill's hardiness rating actually means

Yes — wallich's 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. Wallich's Cranesbill is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for wallich'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 wallich's 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 wallich'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.

Wallich's Cranesbill hardiness — frequently asked questions

Is wallich's cranesbill cold hardy?

Yes — wallich's 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. Wallich's 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 wallich's cranesbill can survive?

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

What hardiness zone is wallich's cranesbill?

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

Can wallich's 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 wallich'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.