Cold hardiness & minimum temperature

Is Curly Parsley (Petroselinum crispum var. crispum)cold hardy? Hardiness zone & min temp

Also called curly parsley, common parsley, garnish parsley.

More about curly parsley

About Curly Parsley

Petroselinum crispum var. crispum · also called curly parsley, common parsley · herb

Curly parsley is a hardy biennial culinary herb prized for its tightly ruffled, deep-green leaves used as a garnish and seasoning. It grows in compact mounds, favors full sun to part shade and rich, moist soil, and is slow to germinate. Treated as an annual, it bolts and seeds in its second season.

Cold limit: USDA 5-9 (grown as annual; overwinters in milder zones) · RHS H5 (7-24°C)

What curly parsley's hardiness rating actually means

Yes — curly parsley is genuinely cold hardy. Rated RHS H5 and USDA 5-9 (grown as annual; overwinters in milder zones), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H5 means: Hardy in most of the UK and in cold winters. On the US scale that maps to USDA 5-9 (grown as annual; overwinters in milder zones) — 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 −15 to −10 °C. Curly Parsley is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for curly parsley as it gets too cold:

It tolerates winter lows to about −15 to −10 °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 curly parsley go outside or overwinter — and where?

Plant it out within USDA 5-9 (grown as annual; overwinters in milder zones) 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 curly parsley can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Curly Parsley hardiness — frequently asked questions

Is curly parsley cold hardy?

Yes — curly parsley is genuinely cold hardy. Rated RHS H5 and USDA 5-9 (grown as annual; overwinters in milder zones), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Curly Parsley is hardy across USDA 5-9 (grown as annual; overwinters in milder zones); 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 curly parsley can survive?

Minimum survivable temperature is roughly about −15 to −10 °C. Curly Parsley is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is curly parsley?

Curly Parsley is rated USDA 5-9 (grown as annual; overwinters in milder zones) and RHS H5 — Hardy in most of the UK and in cold winters.

Can curly parsley survive winter outside?

Plant it out within USDA 5-9 (grown as annual; overwinters in milder zones) 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 curly parsley below its minimum temperature?

It tolerates winter lows to about −15 to −10 °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.