Cold hardiness & minimum temperature

Is Blue Ginger (Dichorisandra thyrsiflora)cold hardy? Hardiness zone & min temp

Also called Blue Spiderwort, Brazilian Blue Ginger, Tropical Blue Ginger.

More about blue ginger

About Blue Ginger

Dichorisandra thyrsiflora · also called Blue Spiderwort, Brazilian Blue Ginger · houseplant

Blue Ginger is a striking Brazilian rainforest plant in the Commelinaceae family, bearing tall upright stems with glossy spirally arranged leaves and vivid deep blue-violet flower spikes in late summer and autumn. Despite its common name it is not a true ginger. A spectacular but demanding tropical houseplant. Toxicity data is limited; classified mildly-toxic out of caution.

Cold limit: USDA 10-11 (indoor-only in temperate climates) · RHS H1b (18-27°C)

Watch for — Stem dieback in winter: Normal dormancy in cooler months. Cut back dead stems and reduce watering; new shoots emerge from the base in spring.

What blue ginger's hardiness rating actually means

Blue 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 10-11 (indoor-only in temperate 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). Blue Ginger has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Blue Ginger hardiness — frequently asked questions

Is blue ginger cold hardy?

Blue 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. Blue Ginger can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (indoor-only in temperate climates)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature blue ginger can survive?

Minimum survivable temperature is roughly about 10 °C (sustained cold below this is damaging). Blue Ginger has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is blue ginger?

Blue Ginger is rated USDA 10-11 (indoor-only in temperate climates) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can blue 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 blue 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.