Cold hardiness & minimum temperature

Is Grayleaf Cranesbill (Geranium cinereum)cold hardy? Hardiness zone & min temp

Also called Grayleaf Cranesbill, Ashy Cranesbill, Grey-Leaved Cranesbill.

More about grayleaf cranesbill

About Grayleaf Cranesbill

Geranium cinereum · also called Grayleaf Cranesbill, Ashy Cranesbill · flowering

Geranium cinereum is a compact alpine perennial native to the Pyrenees and adjacent mountains of northern Spain and southern France, forming tidy low clumps of grey-green, deeply divided leaves. It produces a long succession of pale pink to white flowers with dark purple veining from late spring to midsummer, making it ideal for rock gardens, troughs, and the front of well-drained borders. Sharp drainage is the single most critical care requirement; this plant will rot quickly in wet, poorly drained soils. True Geranium species are non-toxic to cats and dogs per ASPCA guidance.

Cold limit: USDA 5-8 · RHS H6 (-20 to 25°C)

Watch for — Root and crown rot: The most serious threat; caused by waterlogged soil, especially in wet UK winters. Plant on a raised alpine bed, surround the crown with a collar of coarse grit, and ensure water drains freely away from the roots at all times.

What grayleaf cranesbill's hardiness rating actually means

Yes — grayleaf cranesbill is genuinely cold hardy. Rated RHS H6 and USDA 5-8, 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 5-8 — 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. Grayleaf Cranesbill is built for winter — once established it takes hard frost and snow in its stride.

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

Plant it out within USDA 5-8 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 grayleaf cranesbill can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Grayleaf Cranesbill hardiness — frequently asked questions

Is grayleaf cranesbill cold hardy?

Yes — grayleaf cranesbill is genuinely cold hardy. Rated RHS H6 and USDA 5-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Grayleaf Cranesbill is hardy across USDA 5-8; 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 grayleaf cranesbill can survive?

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

What hardiness zone is grayleaf cranesbill?

Grayleaf Cranesbill is rated USDA 5-8 and RHS H6 — Hardy throughout the UK and northern Europe.

Can grayleaf cranesbill survive winter outside?

Plant it out within USDA 5-8 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 grayleaf 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.