Cold hardiness & minimum temperature

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

Also called fragrant white begonia, scented begonia.

More about begonia odorata

About Begonia odorata

Begonia odorata · also called fragrant white begonia, scented begonia · houseplant

Begonia odorata is a scented cane-type begonia bearing clusters of lightly fragrant white-to-pink-blushed flowers above glossy green leaves on upright stems. Unusual among begonias for its perfume, it flowers over a long warm season. Grown indoors or as a frost-tender patio plant, it wants bright-indirect light, even moisture, warmth, and regular feeding to keep blooming.

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

Watch for — Bud drop: Sudden temperature changes, drafts, or drought stress make buds abort. Maintain steady warmth and even soil moisture while it is in bud and bloom.

What begonia odorata's hardiness rating actually means

Begonia odorata 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 or summer patio in most US regions) — 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 odorata has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Begonia odorata hardiness — frequently asked questions

Is begonia odorata cold hardy?

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

What is the minimum temperature begonia odorata can survive?

What hardiness zone is begonia odorata?

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

Can begonia odorata 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 odorata 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.