Cold hardiness & minimum temperature

Is Cow Parsley (Anthriscus sylvestris)cold hardy? Hardiness zone & min temp

Also called Cow Parsley, Wild Chervil, Queen Anne's Lace, Keck.

More about cow parsley

About Cow Parsley

Anthriscus sylvestris · also called Cow Parsley, Wild Chervil · flowering

Anthriscus sylvestris is a robust biennial or short-lived perennial native to Europe, western Asia, and northwestern Africa, and one of the most familiar hedgerow and woodland-edge wildflowers in the British Isles. It produces finely divided, fern-like foliage and large flat-topped umbels of tiny white flowers from April to June. The most important care fact is that it self-seeds prolifically and can quickly colonise an area; deadhead before seed sets if spread is unwanted. The plant contains furocoumarins that cause phototoxic skin reactions and is considered mildly to moderately harmful if ingested by cats or dogs.

Cold limit: USDA 4-8 · RHS H6 (-20 to 25°C)

What cow parsley's hardiness rating actually means

Yes — cow parsley is genuinely cold hardy. Rated RHS H6 and USDA 4-8, 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 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 about −20 to −15 °C. Cow Parsley is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for cow parsley 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 cow parsley 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 cow parsley can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H6 figure above.

Cow Parsley hardiness — frequently asked questions

Is cow parsley cold hardy?

Yes — cow parsley is genuinely cold hardy. Rated RHS H6 and USDA 4-8, it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Cow Parsley 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 cow parsley can survive?

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

What hardiness zone is cow parsley?

Cow Parsley is rated USDA 4-8 and RHS H6 — Hardy throughout the UK and northern Europe.

Can cow parsley 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 cow parsley 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.