Cold hardiness & minimum temperature

Is Cilantro / coriander (Coriandrum sativum)cold hardy? Hardiness zone & min temp

Also called cilantro, coriander, Chinese parsley.

About Cilantro / coriander

Coriandrum sativum · also called cilantro, coriander · herb

Cilantro (the leaves) and coriander (the seeds) are the two crops from the same fast-growing annual. It bolts quickly in heat, so successional sowing every 2-3 weeks is the secret to a steady leaf supply. Pet-safe by ASPCA standards.

Coriandrum sativum, a cool-season annual native to southern Europe and Asia, is the same plant for both leaf (cilantro) and seed (coriander).

Bolts readily under high temperatures and long days, switching from broad leaves to lacy foliage; leaves harvest in 45-80 days, seed needs 100+ days.

Cold limit: USDA 2-11 as an annual · RHS H3 (15-24°C)

Sources: hort.extension.wisc.edu, extension.oregonstate.edu

What cilantro / coriander's hardiness rating actually means

Cilantro / coriander is half-hardy (RHS H3). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. 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 as an 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

Minimum survivable temperature is roughly about −5 to 1 °C — a light, short frost only. Cilantro / coriander shrugs off cold nights but a real, sustained freeze will kill it.

Concretely, for cilantro / coriander as it gets too cold:

Down to roughly about −5 to 1 °C it copes, especially if dry and sheltered.
A sustained hard frost collapses the top growth; whether it returns depends on whether the roots, crown or tubers froze.
Wet cold is far more lethal than dry cold for this plant — soggy, frozen soil is the usual killer.

Can cilantro / coriander go outside or overwinter — and where?

It can live outside year-round only in the mildest, most sheltered part of USDA 2-11 as an annual or a frost-free UK microclimate.
In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter.
A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

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 cilantro / coriander 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 cilantro / coriander

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

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost.
Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse.
Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones.
Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.

Cilantro / coriander hardiness — frequently asked questions

Is cilantro / coriander cold hardy?

Cilantro / coriander is half-hardy (RHS H3). It survives a mild winter outdoors in a sheltered spot, but a hard frost kills it — so in colder zones it is lifted, potted, or grown as a tender plant. Borderline outdoors. In its mild end of USDA 2-11 as an annual (and sheltered UK gardens) cilantro / coriander can stay out; in colder areas it must be lifted, brought in, or treated as a frost-tender plant.

What is the minimum temperature cilantro / coriander can survive?

Minimum survivable temperature is roughly about −5 to 1 °C — a light, short frost only. Cilantro / coriander shrugs off cold nights but a real, sustained freeze will kill it.

What hardiness zone is cilantro / coriander?

Cilantro / coriander is rated USDA 2-11 as an annual and RHS H3 — Half-hardy — comes through mild UK winters outside but is killed by a hard freeze.

Can cilantro / coriander survive winter outside?

It can live outside year-round only in the mildest, most sheltered part of USDA 2-11 as an annual or a frost-free UK microclimate. In colder zones, grow it in a pot you can move under cover, or lift its tubers/roots and store them frost-free over winter. A south-facing wall, free-draining soil and a dry winter position can push it a full zone hardier than the books suggest.

How do I protect cilantro / coriander from frost?

Mulch the crown or root zone deeply with bark, straw or leaf-mould before the first hard frost. Move container plants against a warm wall or into an unheated but frost-free porch or greenhouse. Fleece the top growth on the coldest nights, and keep it on the dry side — dry roots survive cold far better than wet ones. Lift dahlia-type tubers or tender crowns after the first light frost blackens the foliage and store them somewhere cool but frost-free.