Cold hardiness & minimum temperature

Is Round Cardamom (Amomum compactum)cold hardy? Hardiness zone & min temp

Also called Round Cardamom, Java Cardamom, Siam Cardamom, Cluster Cardamom.

More about round cardamom

About Round Cardamom

Amomum compactum · also called Round Cardamom, Java Cardamom · edible

Amomum compactum is a robust, rhizomatous perennial native to the rainforests of Java, Sumatra, and the broader Indonesian archipelago, cultivated across tropical Asia for its round, white pods used in Chinese medicine and as a spice in Indonesian cuisine. It produces dense clusters of leafy stems and flowers directly at ground level, with the round seedpods forming at the base of the plant. The most important care fact is that its roots must be kept constantly moist — this species naturally grows where soils rarely if ever dry out. Its ASPCA toxicity status is not specifically listed; classified as mildly-toxic due to the aromatic essential oils present across the Amomum genus.

Cold limit: USDA 10–12 (indoor in most climates) · RHS H1b (20–32°C; minimum 15°C)

What round cardamom's hardiness rating actually means

Round Cardamom 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 H1b means: Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season. On the US scale that maps to USDA 10–12 (indoor in most climates) — 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 10 °C (sustained cold below this is damaging). Round Cardamom has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for round cardamom as it gets too cold:

Below about about 10 °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 round cardamom go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 10 °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 round cardamom can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Round Cardamom hardiness — frequently asked questions

Is round cardamom cold hardy?

Round Cardamom 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. Round Cardamom can only live outside year-round in genuinely frost-free climates (roughly USDA 10–12 (indoor in most climates)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature round cardamom can survive?

What hardiness zone is round cardamom?

Round Cardamom is rated USDA 10–12 (indoor in most climates) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can round cardamom survive winter outside?

It can holiday outdoors in summer once nights are reliably above 10 °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 round cardamom below its minimum temperature?

Below about about 10 °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.