Cold hardiness & minimum temperature

Is Anne Thomson Cranesbill (Geranium 'Anne Thomson')cold hardy? Hardiness zone & min temp

Also called Anne Thomson Cranesbill, Anne Thomson Geranium.

More about anne thomson cranesbill

About Anne Thomson Cranesbill

Geranium 'Anne Thomson' · also called Anne Thomson Cranesbill, Anne Thomson Geranium · flowering

Geranium 'Anne Thomson' is a hybrid of G. procurrens and G. psilostemon bred by Alan Bremner of Orkney, closely related to 'Ann Folkard' but selected for improved heat tolerance and a more compact, less-sprawling habit. The bright chartreuse young leaves mature to mid-green, and large magenta-pink flowers with a black eye and dark veins are produced abundantly all summer. The RHS awarded it AGM status in 2005. The most important care fact is to site it in sun with well-drained soil and allow space for the trailing stems. ASPCA's 'Geranium' toxic listing refers to Pelargonium; true cranesbills are not confirmed non-toxic by ASPCA, so treat with caution around pets.

Cold limit: USDA 5-9 · RHS H7 (-20°C to 32°C)

What anne thomson cranesbill's hardiness rating actually means

Yes — anne thomson cranesbill is genuinely cold hardy. Rated RHS H7 and USDA 5-9, 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 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 below about −20 °C. Anne Thomson Cranesbill is built for winter — once established it takes hard frost and snow in its stride.

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

Anne Thomson Cranesbill hardiness — frequently asked questions

Is anne thomson cranesbill cold hardy?

Yes — anne thomson cranesbill is genuinely cold hardy. Rated RHS H7 and USDA 5-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Anne Thomson 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 anne thomson cranesbill can survive?

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

What hardiness zone is anne thomson cranesbill?

Anne Thomson Cranesbill is rated USDA 5-9 and RHS H7 — Hardy in the severest European continental winters.

Can anne thomson 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 anne thomson 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.