Cold hardiness & minimum temperature

Is Fingerroot Ginger (Boesenbergia rotunda)cold hardy? Hardiness zone & min temp

Also called fingerroot ginger, Chinese keys, lesser galangal, krachai.

More about fingerroot ginger

About Fingerroot Ginger

Boesenbergia rotunda · also called fingerroot ginger, Chinese keys · herb

Boesenbergia rotunda is a compact rhizomatous herb in the Zingiberaceae family, native to tropical Southeast Asia (Thailand, Indonesia, Malaysia), where it grows in moist, shaded forest margins. The plant produces finger-like yellowish rhizomes that are a prized culinary spice and medicinal ingredient across Southeast Asian cooking, and the most critical care point is keeping the rhizome warm and the soil consistently moist during the growing season. It goes fully dormant in winter, at which point rhizomes should be lifted and stored cool and dry until spring. The plant is not listed on the ASPCA database; given its established culinary use in humans and the non-toxic status of closely related Zingiberaceae genera in the ASPCA database, it is considered mildly-toxic as a precaution.

Cold limit: USDA 9-11 (indoor or lifted in cooler zones) · RHS H1b (20–35 °C)

Watch for — Rhizome rot in dormancy: If left in wet soil over winter, rhizomes rot quickly; lift and store them in a cool, dry paper bag or dry compost at around 10–15 °C until spring.

What fingerroot ginger's hardiness rating actually means

Fingerroot Ginger 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 9-11 (indoor or lifted in cooler zones) — 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). Fingerroot Ginger has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for fingerroot ginger 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 fingerroot ginger 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 fingerroot ginger can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Fingerroot Ginger hardiness — frequently asked questions

Is fingerroot ginger cold hardy?

Fingerroot Ginger 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. Fingerroot Ginger can only live outside year-round in genuinely frost-free climates (roughly USDA 9-11 (indoor or lifted in cooler zones)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature fingerroot ginger can survive?

What hardiness zone is fingerroot ginger?

Fingerroot Ginger is rated USDA 9-11 (indoor or lifted in cooler zones) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can fingerroot ginger 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 fingerroot ginger 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.