Cold hardiness & minimum temperature

Is Begonia schmidtiana (Begonia schmidtiana)cold hardy? Hardiness zone & min temp

Also called Schmidt's begonia, schmidtiana begonia.

More about begonia schmidtiana

About Begonia schmidtiana

Begonia schmidtiana · also called Schmidt's begonia, schmidtiana begonia · flowering

Begonia schmidtiana is a small, bushy Brazilian species with soft, hairy bronze-green leaves with reddish undersides and near-constant clusters of pale pink to white flowers. Compact and free-flowering, it suits bright windowsills and dish gardens. Keep the airy mix lightly moist, give it warmth and humidity, and water at the base to protect the fuzzy leaves from rot.

Cold limit: USDA 10-11 (grown indoors in most of the US and UK) · RHS H1b (18-26°C)

Watch for — Bud or flower drop: Sudden drops in humidity, temperature swings, or inconsistent watering can shed buds. Keep conditions steady, warm, and moderately humid.

What begonia schmidtiana's hardiness rating actually means

Begonia schmidtiana 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 (grown indoors in most of the US and UK) — 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). Begonia schmidtiana has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Begonia schmidtiana hardiness — frequently asked questions

Is begonia schmidtiana cold hardy?

Begonia schmidtiana 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. Begonia schmidtiana can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (grown indoors in most of the US and UK)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature begonia schmidtiana can survive?

What hardiness zone is begonia schmidtiana?

Begonia schmidtiana is rated USDA 10-11 (grown indoors in most of the US and UK) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can begonia schmidtiana 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 begonia schmidtiana 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.