Cold hardiness & minimum temperature

Is Neon Tangerine Calendula (Calendula officinalis)cold hardy? Hardiness zone & min temp

Also called Neon Tangerine Pot Marigold, Pot Marigold, English Marigold.

More about neon tangerine calendula

About Neon Tangerine Calendula

Calendula officinalis · also called Neon Tangerine Pot Marigold, Pot Marigold · flowering

Neon Tangerine Calendula is a vivid, single-to-semi-double cultivar with intense orange blooms that glow in full sun. A cool-season annual that blooms prolifically from late spring and can repeat through autumn with deadheading. The ASPCA lists Calendula as mildly toxic; ingestion may cause mild gastric irritation in pets.

Cold limit: USDA 2-11 (cool-season annual) · RHS H3 (7-24°C)

Watch for — Heat-induced flowering pause: Calendula ceases flowering above about 27°C; cut back and water well to encourage a flush of autumn blooms once temperatures drop.

What neon tangerine calendula's hardiness rating actually means

Hardiness works differently for neon tangerine calendula: 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 H3 means: Half-hardy — comes through mild UK winters outside but is killed by a hard freeze. On the US scale that maps to USDA 2-11 (cool-season annual) — 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 neon tangerine calendula 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 neon tangerine calendula 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 neon tangerine calendula can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H3 figure above.

Frost protection for borderline neon tangerine calendula

Neon Tangerine Calendula 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.

Neon Tangerine Calendula hardiness — frequently asked questions

Is neon tangerine calendula cold hardy?

Hardiness works differently for neon tangerine calendula: 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. Neon Tangerine Calendula is grown 2-11 (cool-season annual); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature neon tangerine calendula 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 neon tangerine calendula?

Neon Tangerine Calendula is rated USDA 2-11 (cool-season annual) and RHS H3 — Half-hardy — comes through mild UK winters outside but is killed by a hard freeze.

Can neon tangerine calendula 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 neon tangerine calendula 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.