Cold hardiness & minimum temperature

Is Dill (Anethum graveolens)cold hardy? Hardiness zone & min temp

Also called common dill, dill weed.

About Dill

Anethum graveolens · also called common dill, dill weed · herb

Dill is an annual herb in the carrot family grown for feathery foliage (dill weed) and aromatic seeds. Direct-sow in succession; it bolts fast in heat. Host plant for swallowtail butterflies. Pet-safe in culinary amounts.

Anethum graveolens, an aromatic annual (sometimes biennial) umbellifer of the carrot family, grown for its finely dissected blue-green foliage and flat umbels of tiny yellow flowers.

Short-lived once it flowers, so sow successionally through the season for continuous leaf; leave a few plants to set seed for both pickling heads and self-seeded volunteers.

Cold limit: USDA Grown as an annual in zones 3-11 · RHS H4 (15-24°C)

Sources: extension.umn.edu, extension.illinois.edu, rhs.org.uk

What dill's hardiness rating actually means

Hardiness works differently for dill: 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 H4 means: Hardy in an average winter across much of the temperate world. On the US scale that maps to USDA Grown as an annual in zones 3-11 — 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 dill 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 dill 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 dill 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 dill

Dill 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.

Dill hardiness — frequently asked questions

Is dill cold hardy?

Hardiness works differently for dill: 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. Dill is grown Grown as an annual in zones 3-11; you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature dill 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 dill?

Dill is rated USDA Grown as an annual in zones 3-11 and RHS H4 — Hardy in an average winter across much of the temperate world.

Can dill 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 dill 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.