Cold hardiness & minimum temperature

Is Celery (Apium graveolens var. dulce)cold hardy? Hardiness zone & min temp

Also called Celery, Stalk celery, Pascal celery.

More about celery

About Celery

Apium graveolens var. dulce · also called Celery, Stalk celery · edible

Celery is a cool-season biennial grown as an annual for its crisp, ribbed stalks and aromatic leaves. It demands consistently moist, rich soil and a long cool growing season of 100–130 days. Self-blanching varieties produce pale, tender stalks without earthing up; trench varieties need soil mounded around stems for sweetness.

Cold limit: USDA 5-9 · RHS H6 (15–21°C)

Watch for — Bolting: Exposure to temperatures below 10°C for 10+ consecutive days triggers premature flowering, making stalks tough and bitter. Plant out only after soil has warmed and protect young transplants from cold snaps with fleece.

What celery's hardiness rating actually means

Hardiness works differently for celery: it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". Its RHS rating of H6 means: Hardy throughout the UK and northern Europe. On the US scale that maps to USDA 5-9 — 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

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

Concretely, for celery as it gets too cold:

Light frost (around 0 to −2 °C) damages or kills tender summer crops outright; cold-hardy types take a few degrees of frost.
The plant does not "survive winter" — its life cycle simply ends, by design, when frost arrives or it finishes cropping.
A surprise late spring frost can also kill young transplants set out too early, before the season even starts.

Can celery go outside or overwinter — and where?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost.
In short-season zones, start it indoors or under cover to stretch the effective growing window.
Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

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

Frost protection for borderline celery

Celery is right on a hardiness edge in many gardens, so if you are pushing it, these measures buy it the margin it needs:

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks.
Have row cover ready for an unexpected late spring or early autumn frost.
Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.

Celery hardiness — frequently asked questions

Is celery cold hardy?

Hardiness works differently for celery: it is grown as a seasonal crop, not overwintered. The question is not "what zone" but "how long is your frost-free growing window". A seasonal crop, not a perennial. Celery is grown as an annual in USDA 5-9; you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature celery can survive?

As an annual crop, its "minimum temperature" is the first hard frost — that is the end of the plant's life, not a survivable low. Many types are also damaged by light frost (around 0 °C).

What hardiness zone is celery?

Celery is rated USDA 5-9 and RHS H6 — Hardy throughout the UK and northern Europe.

Can celery survive winter outside?

Time it to your frost dates: sow or plant out after the last spring frost, and aim to harvest before the first autumn frost. In short-season zones, start it indoors or under cover to stretch the effective growing window. Hardier crops in this group can be sown for an autumn or overwintered harvest in mild zones — check the specific crop.

How do I protect celery from frost?

Use fleece, cloches or a cold frame at each end of the season to dodge a borderline frost and add growing weeks. Have row cover ready for an unexpected late spring or early autumn frost. Know your local last- and first-frost dates and count back the crop’s days-to-maturity to schedule the sowing.