Cold hardiness & minimum temperature

Is Purging Jatropha (Jatropha cathartica)cold hardy? Hardiness zone & min temp

Also called Purging Jatropha, Berlandier's Nettlespurge.

More about purging jatropha

About Purging Jatropha

Jatropha cathartica · also called Purging Jatropha, Berlandier's Nettlespurge · tropical

Purging Jatropha is a compact, caudiciform succulent from the Chihuahuan Desert of Mexico and southern Texas. It produces a woody, globe-shaped underground caudex from which slender stems carry deeply lobed, blue-green leaves. Small coral-red flowers appear in summer. Highly drought-adapted and suited to container culture by experienced succulent growers.

Cold limit: USDA 10a-11 · RHS H1c (5 to 40 °C)

Watch for — Caudex rot: Overwatering during dormancy or in cool conditions causes the caudex to rot internally, often without external warning. Use an extremely free-draining mix, withhold water in winter, and avoid low temperatures combined with moisture.

What purging jatropha's hardiness rating actually means

Purging Jatropha is not cold hardy. It is a tropical houseplant that dies if it is left out through frost — there is no zone where it overwinters outdoors in a UK or cold-US climate. Its RHS rating of H1c means: Warm-temperate — can summer outdoors but must come in well before the first frost. On the US scale that maps to USDA 10a-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

Minimum survivable temperature is roughly about 5 °C (and never frost). Purging Jatropha has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for purging jatropha as it gets too cold:

Below about about 5 °C, growth stalls and the leaves start to show cold stress — dark, water-soaked, or yellowing patches.
A single light frost blackens the foliage; a hard freeze kills the whole plant, roots included, and it does not recover.
Even a cold, draughty windowsill or an unheated porch in winter can be enough to damage it permanently.

Can purging jatropha go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 5 °C, in shade or dappled light, hardened off gradually.
Bring it back indoors well before the first autumn frost — do not wait for a frost warning, move it when nights drop toward 10-12 °C.
It will never overwinter outside in a temperate climate; the indoors is its winter home, full stop.

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 purging jatropha can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Purging Jatropha hardiness — frequently asked questions

Is purging jatropha cold hardy?

Purging Jatropha is not cold hardy. It is a tropical houseplant that dies if it is left out through frost — there is no zone where it overwinters outdoors in a UK or cold-US climate. Indoor-only in almost every home. Purging Jatropha can only live outside year-round in genuinely frost-free climates (roughly USDA 10a-11); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature purging jatropha can survive?

Minimum survivable temperature is roughly about 5 °C (and never frost). Purging Jatropha has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is purging jatropha?

Purging Jatropha is rated USDA 10a-11 and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can purging jatropha survive winter outside?

It can holiday outdoors in summer once nights are reliably above 5 °C, in shade or dappled light, hardened off gradually. Bring it back indoors well before the first autumn frost — do not wait for a frost warning, move it when nights drop toward 10-12 °C. It will never overwinter outside in a temperate climate; the indoors is its winter home, full stop.

What happens to purging jatropha below its minimum temperature?

Below about about 5 °C, growth stalls and the leaves start to show cold stress — dark, water-soaked, or yellowing patches. A single light frost blackens the foliage; a hard freeze kills the whole plant, roots included, and it does not recover. Even a cold, draughty windowsill or an unheated porch in winter can be enough to damage it permanently.