Cold hardiness & minimum temperature

Is Tall Sinningia (Sinningia elatior)cold hardy? Hardiness zone & min temp

Also called Tall Sinningia, Elatior Sinningia.

More about tall sinningia

About Tall Sinningia

Sinningia elatior · also called Tall Sinningia, Elatior Sinningia · tropical

Sinningia elatior is one of the taller-growing species in the genus, a tuberous perennial native to open terrestrial habitats in southern Brazil and northeastern Argentina where it grows in full sun with its large tubers buried well below the soil surface. It produces tall upright stems bearing pale red to orange-red tubular flowers held horizontally in the leaf axils, designed for hummingbird pollination. In cultivation, it appreciates a brighter position than many Sinningias and a defined winter rest period to build the tuber before reflowering. The ASPCA lists Sinningia (Gloxinia) as non-toxic to cats and dogs.

Cold limit: USDA 10-12 (indoor in most climates) · RHS H1b (16–28°C)

Watch for — Tuber failure after insufficient rest: Large tubers that are not given a proper dry winter rest may produce weak growth the following season or fail to flower; allow the foliage to die back fully and rest the tuber barely moist for at least 8–10 weeks.

What tall sinningia's hardiness rating actually means

Tall Sinningia 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). Tall Sinningia has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Tall Sinningia hardiness — frequently asked questions

Is tall sinningia cold hardy?

Tall Sinningia 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. Tall Sinningia 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 tall sinningia can survive?

What hardiness zone is tall sinningia?

Tall Sinningia 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 tall sinningia 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 tall sinningia 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.