Cold hardiness & minimum temperature

Is Geranium wallichianum 'Syabru' (Geranium wallichianum 'Syabru')cold hardy? Hardiness zone & min temp

Also called Syabru cranesbill.

More about geranium wallichianum 'syabru'

About Geranium wallichianum 'Syabru'

Geranium wallichianum 'Syabru' · also called Syabru cranesbill · flowering

A wild-collected wallichianum cranesbill with long, scrambling stems bearing saucer-shaped, deep violet-blue to magenta-pink flowers with a paler centre, blooming profusely from midsummer to the first frosts. 'Syabru' weaves through borders and over edges to give weeks of late colour. Hardy and vigorous, it is valued for its long flowering season and its ability to mingle among other plants.

Cold limit: USDA 5-8 (hardy garden perennial) · RHS H4 (-10 to 27°C)

What geranium wallichianum 'syabru''s hardiness rating actually means

Yes — geranium wallichianum 'syabru' is genuinely cold hardy. Rated RHS H4 and USDA 5-8 (hardy garden perennial), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H4 means: Hardy in an average winter across much of the temperate world. On the US scale that maps to USDA 5-8 (hardy garden perennial) — 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 −10 to −5 °C. Geranium wallichianum 'Syabru' is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for geranium wallichianum 'syabru' as it gets too cold:

It tolerates winter lows to about −10 to −5 °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 geranium wallichianum 'syabru' go outside or overwinter — and where?

Plant it out within USDA 5-8 (hardy garden perennial) 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 geranium wallichianum 'syabru' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Geranium wallichianum 'Syabru' hardiness — frequently asked questions

Is geranium wallichianum 'syabru' cold hardy?

Yes — geranium wallichianum 'syabru' is genuinely cold hardy. Rated RHS H4 and USDA 5-8 (hardy garden perennial), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Geranium wallichianum 'Syabru' is hardy across USDA 5-8 (hardy garden perennial); 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 geranium wallichianum 'syabru' can survive?

Minimum survivable temperature is roughly about −10 to −5 °C. Geranium wallichianum 'Syabru' is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is geranium wallichianum 'syabru'?

Geranium wallichianum 'Syabru' is rated USDA 5-8 (hardy garden perennial) and RHS H4 — Hardy in an average winter across much of the temperate world.

Can geranium wallichianum 'syabru' survive winter outside?

Plant it out within USDA 5-8 (hardy garden perennial) 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 geranium wallichianum 'syabru' below its minimum temperature?

It tolerates winter lows to about −10 to −5 °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.