Cold hardiness & minimum temperature

Is Pires's Sinningia (Sinningia piresiana)cold hardy? Hardiness zone & min temp

Also called Pires's Sinningia.

More about pires's sinningia

About Pires's Sinningia

Sinningia piresiana · also called Pires's Sinningia · flowering

Sinningia piresiana is a tuberous caudiciform gesneriad from Brazil, valued among collectors for its silvery, white-haired foliage arranged in a whorl of six leaves atop a compact stem, and its cherry-pink tubular flowers with prominent crimson stripes towards the throat. In general habit it resembles the closely related S. canescens and S. leucotricha. After flowering the plant goes dormant, dying back to the tuber until conditions trigger regrowth. 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 (16–26 °C in growth; above 10 °C during dormancy)

Watch for — Tuber rot from excess moisture during dormancy: Keeping a dormant tuber in wet compost is the leading cause of loss; as soon as leaves die back, reduce watering to the barest minimum and store in a dry, cool but frost-free spot.

What pires's sinningia's hardiness rating actually means

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

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

Pires's Sinningia hardiness — frequently asked questions

Is pires's sinningia cold hardy?

Pires's 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. Pires's 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 pires's sinningia can survive?

What hardiness zone is pires's sinningia?

Pires's 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 pires's 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 pires's 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.