Cold hardiness & minimum temperature

Is Cup Ginger (Hornstedtia scyphifera)cold hardy? Hardiness zone & min temp

Also called Beehive Ginger relative, Malayan Cup Ginger.

More about cup ginger

About Cup Ginger

Hornstedtia scyphifera · also called Beehive Ginger relative, Malayan Cup Ginger · tropical

Hornstedtia scyphifera is a tall Malaysian ginger-family plant with dramatic cup-shaped reddish bracts that emerge from basal sheaths at ground level. A striking tropical collector's plant, it requires consistently warm and humid conditions. Not individually listed by the ASPCA; rated mildly-toxic as a precaution for the Zingiberaceae family.

Cold limit: USDA 12-13 · RHS H1a (20-35°C)

Watch for — Reluctance to flower: Requires mature rhizomes and consistently warm (above 22°C) temperatures to flower reliably. Young plants or those in cool conditions rarely produce the ornamental bracts.

What cup ginger's hardiness rating actually means

Cup 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 H1a means: Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever. On the US scale that maps to USDA 12-13 — 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 above about 15 °C (warm, never cold). Cup Ginger has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for cup ginger as it gets too cold:

Below about above about 15 °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 cup ginger go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above above 15 °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 cup ginger can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1a figure above.

Cup Ginger hardiness — frequently asked questions

Is cup ginger cold hardy?

Cup 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. Cup Ginger can only live outside year-round in genuinely frost-free climates (roughly USDA 12-13); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature cup ginger can survive?

Minimum survivable temperature is roughly above about 15 °C (warm, never cold). Cup Ginger has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is cup ginger?

Cup Ginger is rated USDA 12-13 and RHS H1a — Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever.

Can cup ginger survive winter outside?

It can holiday outdoors in summer once nights are reliably above above 15 °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 cup ginger below its minimum temperature?

Below about above about 15 °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.