Cold hardiness & minimum temperature

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

Also called orange spot begonia, dichroa cane begonia.

More about begonia dichroa

About Begonia dichroa

Begonia dichroa · also called orange spot begonia, dichroa cane begonia · houseplant

Begonia dichroa is a compact Brazilian cane-type begonia with glossy green leaves often flecked with silver and clusters of bright orange flowers that appear on and off through the year. More compact than typical angel wings, it suits windowsills and shelves. Give it bright indirect light, evenly moist well-drained soil, and warm, humid conditions for steady blooming.

Cold limit: USDA 10-11 (indoor in most US homes) · RHS H1c (18-27°C)

What begonia dichroa's hardiness rating actually means

Begonia dichroa 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 H1c means: Warm-temperate — can summer outdoors but must come in well before the first frost. 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 5 °C (and never frost). Begonia dichroa has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for begonia dichroa as it gets too cold:

Below about about 5 °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 dichroa go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 5 °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 dichroa can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Begonia dichroa hardiness — frequently asked questions

Is begonia dichroa cold hardy?

Begonia dichroa 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 dichroa 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 dichroa can survive?

Minimum survivable temperature is roughly about 5 °C (and never frost). Begonia dichroa has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is begonia dichroa?

Begonia dichroa is rated USDA 10-11 (indoor in most US homes) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can begonia dichroa survive winter outside?

It can holiday outdoors in summer once nights are reliably above 5 °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 dichroa below its minimum temperature?

Below about about 5 °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.