Cold hardiness & minimum temperature

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

Also called metallic leaf begonia.

More about begonia incarnata

About Begonia incarnata

Begonia incarnata · also called metallic leaf begonia · houseplant

Begonia incarnata is a cane-like, shrubby begonia from Mexico with glossy, pointed leaves that take on a metallic sheen and red-flushed undersides. Upright, branching stems carry clusters of pink flowers over a long season. Easygoing for a begonia, it likes bright-indirect light, even moisture, and warmth, and tolerates ordinary room humidity better than fussier rhizomatous types.

Cold limit: USDA 10-11 (indoor in most US homes) · RHS H1b (16-26°C)

Watch for — Bud or flower drop: Sudden temperature swings, drafts, or drying out can cause buds to abort. Keep conditions steady and the rootball evenly moist during budding.

What begonia incarnata's hardiness rating actually means

Begonia incarnata 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 (indoor in most US homes) — 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 incarnata has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Begonia incarnata hardiness — frequently asked questions

Is begonia incarnata cold hardy?

Begonia incarnata 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 incarnata can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (indoor in most US homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature begonia incarnata can survive?

What hardiness zone is begonia incarnata?

Begonia incarnata is rated USDA 10-11 (indoor in most US homes) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can begonia incarnata 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 incarnata 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.