Cold hardiness & minimum temperature

Is Calendula 'Indian Prince' (Calendula officinalis 'Indian Prince')cold hardy? Hardiness zone & min temp

Also called Indian Prince marigold, dark-centre calendula.

More about calendula 'indian prince'

About Calendula 'Indian Prince'

Calendula officinalis 'Indian Prince' · also called Indian Prince marigold, dark-centre calendula · flowering

Calendula 'Indian Prince' is a tall, robust pot marigold prized for deep burnt-orange flowers with mahogany-red reverses and a dark centre. An easy hardy annual, it flowers prolifically from seed in full sun, resists mildew better than many strains, and the edible petals suit cutting and cottage borders. Deadheading sustains a long, pollinator-friendly display.

Cold limit: USDA Hardy annual; grown as cool-season annual in zones 2-11 (overwinters in 9-11) · RHS H4 (5-25°C)

What calendula 'indian prince''s hardiness rating actually means

Hardiness works differently for calendula 'indian prince': 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 Hardy annual; grown as cool-season annual in zones 2-11 (overwinters in 9-11) — 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 calendula 'indian prince' 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 calendula 'indian prince' 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 calendula 'indian prince' 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 calendula 'indian prince'

Calendula 'Indian Prince' 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.

Calendula 'Indian Prince' hardiness — frequently asked questions

Is calendula 'indian prince' cold hardy?

Hardiness works differently for calendula 'indian prince': 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. Calendula 'Indian Prince' is grown Hardy annual; grown as cool-season annual in zones 2-11 (overwinters in 9-11); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature calendula 'indian prince' 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 calendula 'indian prince'?

Calendula 'Indian Prince' is rated USDA Hardy annual; grown as cool-season annual in zones 2-11 (overwinters in 9-11) and RHS H4 — Hardy in an average winter across much of the temperate world.

Can calendula 'indian prince' 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 calendula 'indian prince' 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.