Cold hardiness & minimum temperature

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

Also called Hamburg parsley, turnip-rooted parsley, root parsley.

More about hamburg parsley

About Hamburg Parsley

Petroselinum crispum var. tuberosum · also called Hamburg parsley, turnip-rooted parsley · edible

Hamburg parsley is a hardy biennial grown for its swollen, parsnip-like white taproot as well as edible parsley-flavored leaves. It needs deep, loose, fertile soil and a long, cool season to size up roots, which sweeten after frost. Sun to part shade and steady moisture give the best yields.

Cold limit: USDA 5-9 (roots overwinter in the ground in many zones) · RHS H5 (7-24°C)

Watch for — Premature bolting: A cold spell on young plants or drought can trigger flowering, halting root growth. Sow after the worst cold passes and keep plants unstressed and well watered.

What hamburg parsley's hardiness rating actually means

Yes — hamburg parsley is genuinely cold hardy. Rated RHS H5 and USDA 5-9 (roots overwinter in the ground in many 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 (roots overwinter in the ground in many 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. Hamburg Parsley is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for hamburg 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 hamburg parsley go outside or overwinter — and where?

Plant it out within USDA 5-9 (roots overwinter in the ground in many 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 hamburg parsley can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H5 figure above.

Hamburg Parsley hardiness — frequently asked questions

Is hamburg parsley cold hardy?

Yes — hamburg parsley is genuinely cold hardy. Rated RHS H5 and USDA 5-9 (roots overwinter in the ground in many zones), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Hamburg Parsley is hardy across USDA 5-9 (roots overwinter in the ground in many 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 hamburg parsley can survive?

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

What hardiness zone is hamburg parsley?

Hamburg Parsley is rated USDA 5-9 (roots overwinter in the ground in many zones) and RHS H5 — Hardy in most of the UK and in cold winters.

Can hamburg parsley survive winter outside?

Plant it out within USDA 5-9 (roots overwinter in the ground in many 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 hamburg 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.