Cold hardiness & minimum temperature

Is Epazote (Dysphania ambrosioides)cold hardy? Hardiness zone & min temp

Also called Mexican Tea, Wormseed.

More about epazote

About Epazote

Dysphania ambrosioides · also called Mexican Tea, Wormseed · herb

Epazote is a pungent, resinous annual or short-lived perennial herb essential to Mexican cooking, especially with beans, where it adds flavour and is said to reduce gassiness. A tough, sun-loving plant of warm climates, it tolerates poor dry soil and grows tall and weedy. Its potent essential oil makes it medicinal and toxic in concentrated form.

Cold limit: USDA 8-11 (perennial in mild areas, grown as an annual elsewhere) · RHS H2 (18-30°C)

Watch for — Frost kill: It is frost-tender and dies back with the first hard freeze in cool climates. Treat as an annual or grow in pots that can be moved under cover.

What epazote's hardiness rating actually means

Hardiness works differently for epazote: 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 H2 means: Tender — survives a frost-free greenhouse or a very mild, sheltered spot. On the US scale that maps to USDA 8-11 (perennial in mild areas, grown as an annual elsewhere) — 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 epazote 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 epazote 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 epazote can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H2 figure above.

Frost protection for borderline epazote

Epazote 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.

Epazote hardiness — frequently asked questions

Is epazote cold hardy?

Hardiness works differently for epazote: 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. Epazote is grown 8-11 (perennial in mild areas, grown as an annual elsewhere); you sow after the last frost and harvest before the first one, then start again next year.

What is the minimum temperature epazote 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 epazote?

Epazote is rated USDA 8-11 (perennial in mild areas, grown as an annual elsewhere) and RHS H2 — Tender — survives a frost-free greenhouse or a very mild, sheltered spot.

Can epazote 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 epazote 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.