Cold hardiness & minimum temperature

Is Begonia 'Braveheart' (Begonia rex-cultorum 'Braveheart')cold hardy? Hardiness zone & min temp

Also called braveheart begonia, rex braveheart.

More about begonia 'braveheart'

About Begonia 'Braveheart'

Begonia rex-cultorum 'Braveheart' · also called braveheart begonia, rex braveheart · houseplant

Begonia 'Braveheart' is a rhizomatous Rex hybrid grown for heart-shaped leaves splashed silver-pink with a near-black central zone and ruby reverse. Foliage is the whole point, so prioritise bright indirect light, steady warmth, and high humidity. Keep the chunky mix lightly moist but never wet, since the shallow rhizome rots fast in soggy soil.

Cold limit: USDA 10-11 (grown indoors in most of the US and UK) · RHS H1b (18-24°C)

Watch for — Crispy brown leaf edges: Usually low humidity or dry air from heating. Raise ambient humidity with a humidifier or pebble tray and keep the plant away from radiators and cold draughts.

What begonia 'braveheart''s hardiness rating actually means

Begonia 'Braveheart' 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 'Braveheart' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Begonia 'Braveheart' hardiness — frequently asked questions

Is begonia 'braveheart' cold hardy?

Begonia 'Braveheart' 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 'Braveheart' 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 'braveheart' can survive?

What hardiness zone is begonia 'braveheart'?

Begonia 'Braveheart' 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 'braveheart' 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 'braveheart' 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.