Cold hardiness & minimum temperature

Is Field marigold (Calendula arvensis)cold hardy? Hardiness zone & min temp

Also called field marigold, wild marigold, corn marigold.

More about field marigold

About Field marigold

Calendula arvensis · also called field marigold, wild marigold · flowering

A compact, free-flowering cool-season annual native to the Mediterranean, producing masses of small yellow to orange daisy-like flowers from spring through autumn. Highly resilient in poor, well-drained soils and full sun, it self-seeds prolifically and is valued both ornamentally and as a companion plant for attracting beneficial insects.

Cold limit: USDA 6–10 (cool-season annual; self-seeds in zones 6–10) · RHS H4 (7–20 °C optimal; tolerates light frost to −5 °C)

What field marigold's hardiness rating actually means

Hardiness works differently for field marigold: 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 6–10 (cool-season annual; self-seeds in zones 6–10) — 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 field marigold 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 field marigold 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 field marigold 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 field marigold

Field marigold 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.

Field marigold hardiness — frequently asked questions

Is field marigold cold hardy?

Hardiness works differently for field marigold: 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. Field marigold is grown 6–10 (cool-season annual; self-seeds in zones 6–10); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature field marigold 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 field marigold?

Field marigold is rated USDA 6–10 (cool-season annual; self-seeds in zones 6–10) and RHS H4 — Hardy in an average winter across much of the temperate world.

Can field marigold 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 field marigold 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.