Cold hardiness & minimum temperature

Is Corsican Heron's Bill (Erodium corsicum)cold hardy? Hardiness zone & min temp

Also called Corsican Heron's Bill, Corsican Stork's Bill.

More about corsican heron's bill

About Corsican Heron's Bill

Erodium corsicum · also called Corsican Heron's Bill, Corsican Stork's Bill · flowering

Erodium corsicum is a compact evergreen perennial native to rocky, sun-baked slopes in Corsica and Sardinia. It thrives in sharply drained, alkaline to neutral soil in full sun and is an excellent candidate for rock gardens, troughs, and dry stone walls. The most important care point is to keep roots consistently dry in winter, as waterlogging rather than frost is the primary cause of death. It is not listed on the ASPCA toxic plant database and the genus is generally considered low-risk to pets.

Cold limit: USDA 7-9 · RHS H4 (-10 to 25°C)

Watch for — Crown rot in wet winters: The most common cause of plant loss; ensure perfectly sharp drainage and apply a grit collar around the crown; consider an open cloche in prolonged wet spells.

What corsican heron's bill's hardiness rating actually means

Yes — corsican heron's bill is genuinely cold hardy. Rated RHS H4 and USDA 7-9, 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 7-9 — 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 −10 to −5 °C. Corsican Heron's Bill is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for corsican heron's bill 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 corsican heron's bill go outside or overwinter — and where?

Plant it out within USDA 7-9 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 corsican heron's bill can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Frost protection for borderline corsican heron's bill

Corsican Heron's Bill is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

At the cold edge of its range, mulch the root zone in late autumn to buffer the deepest freezes.
Protect container specimens — pots freeze through far faster than open ground, costing roughly a zone of hardiness.
Shelter new growth from late spring frosts with fleece if a hard night is forecast.

Corsican Heron's Bill hardiness — frequently asked questions

Is corsican heron's bill cold hardy?

Yes — corsican heron's bill is genuinely cold hardy. Rated RHS H4 and USDA 7-9, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Corsican Heron's Bill is hardy across USDA 7-9; 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 corsican heron's bill can survive?

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

What hardiness zone is corsican heron's bill?

Corsican Heron's Bill is rated USDA 7-9 and RHS H4 — Hardy in an average winter across much of the temperate world.

Can corsican heron's bill survive winter outside?

Plant it out within USDA 7-9 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.

How do I protect corsican heron's bill from frost?

At the cold edge of its range, mulch the root zone in late autumn to buffer the deepest freezes. Protect container specimens — pots freeze through far faster than open ground, costing roughly a zone of hardiness. Shelter new growth from late spring frosts with fleece if a hard night is forecast.