Cold hardiness & minimum temperature

Is Shining Sinningia (Sinningia micans)cold hardy? Hardiness zone & min temp

Also called Shining Sinningia.

More about shining sinningia

About Shining Sinningia

Sinningia micans · also called Shining Sinningia · flowering

Sinningia micans is a striking tuberous gesneriad from São Paulo state, Brazil, notable for its candelabra-like clusters of vivid red tubular flowers that emerge from a whorl of four leaves. The dark red, pebbly calyx completely encloses the corolla in bud, making the plant distinctive even before the flowers open. It can be challenging to bring into bloom — restricting new growth shoots to one or two tips when they sprout helps concentrate the tuber's energy towards flowering. The ASPCA lists the Sinningia genus as non-toxic to cats and dogs; this species is not individually verified.

Cold limit: USDA 10–12 (indoor in most climates) · RHS H1b (18–26 °C in growth; above 10 °C during dormancy)

What shining sinningia's hardiness rating actually means

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

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

Shining Sinningia hardiness — frequently asked questions

Is shining sinningia cold hardy?

Shining 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. Shining 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 shining sinningia can survive?

What hardiness zone is shining sinningia?

Shining 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 shining 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 shining 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.