Cold hardiness & minimum temperature

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

Also called Delicious begonia.

More about delicious begonia

About Delicious Begonia

Begonia deliciosa · also called Delicious begonia · tropical

Begonia deliciosa is a rare collector's species with an unresolved taxonomic placement (listed as a name of uncertain status in Plants of the World Online), cultivated in specialist collections for its distinctive foliage. As with other tropical begonias it thrives in bright indirect light, high humidity, and well-draining compost, and is most successfully grown in a humid greenhouse or enclosed cabinet. The most critical care point is maintaining consistently high humidity of 60–80%. Toxic to cats, dogs, and horses.

Cold limit: USDA 11–12 (indoor in most climates) · RHS H1a (18–27°C)

What delicious begonia's hardiness rating actually means

Delicious Begonia 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 H1a means: Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever. On the US scale that maps to USDA 11–12 (indoor in most climates) — 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 above about 15 °C (warm, never cold). Delicious Begonia has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for delicious begonia as it gets too cold:

Below about above about 15 °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 delicious begonia go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above above 15 °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 delicious begonia can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1a figure above.

Delicious Begonia hardiness — frequently asked questions

Is delicious begonia cold hardy?

Delicious Begonia 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. Delicious Begonia can only live outside year-round in genuinely frost-free climates (roughly USDA 11–12 (indoor in most climates)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature delicious begonia can survive?

Minimum survivable temperature is roughly above about 15 °C (warm, never cold). Delicious Begonia has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is delicious begonia?

Delicious Begonia is rated USDA 11–12 (indoor in most climates) and RHS H1a — Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever.

Can delicious begonia survive winter outside?

It can holiday outdoors in summer once nights are reliably above above 15 °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 delicious begonia below its minimum temperature?

Below about above about 15 °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.