Cold hardiness & minimum temperature

Is Druce's Cranesbill (Geranium × oxonianum)cold hardy? Hardiness zone & min temp

Also called Druce's cranesbill, Oxford cranesbill, hybrid cranesbill.

More about druce's cranesbill

About Druce's Cranesbill

Geranium × oxonianum · also called Druce's cranesbill, Oxford cranesbill · flowering

Geranium × oxonianum is a vigorous hybrid cranesbill (G. endressii × G. versicolor) that arose naturally near Oxford and was first described by G.C. Druce, hence the common name. It forms spreading, semi-evergreen mounds and produces an extremely long succession of funnel-shaped pink flowers — typically deeper pink than G. endressii, with darker veining inherited from G. versicolor — from late spring right through autumn. Its vigour, ground-covering ability, and tolerance of sun or shade make it one of the most useful border perennials available. Considered non-toxic to cats and dogs.

Cold limit: USDA 4-8 · RHS H7 (-20 to 25°C)

What druce's cranesbill's hardiness rating actually means

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

Concretely, for druce's cranesbill 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 druce'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 druce's cranesbill can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H7 figure above.

Druce's Cranesbill hardiness — frequently asked questions

Is druce's cranesbill cold hardy?

Yes — druce's cranesbill 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. Druce'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 druce's cranesbill can survive?

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

What hardiness zone is druce's cranesbill?

Druce's Cranesbill is rated USDA 4-8 and RHS H7 — Hardy in the severest European continental winters.

Can druce'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 druce's cranesbill 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.