Cold hardiness & minimum temperature

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

Also called Socotra begonia, Socotra Island begonia.

More about socotra begonia

About Socotra Begonia

Begonia socotrana · also called Socotra begonia, Socotra Island begonia · flowering

Begonia socotrana is a bulbous-rooted species native to the island of Socotra in the Arabian Sea, historically significant as one of the parents of the modern winter-flowering Hiemalis (Elatior) begonia hybrids. Unlike most begonias it grows during the cooler months and goes dormant in summer heat, producing cheerful pink flowers in autumn and winter when few houseplants bloom. Its seasonal growth cycle means it must be kept dry and cool during summer dormancy or the bulbs rot. This plant is toxic to cats and dogs.

Cold limit: USDA 10-12 (indoor in most climates) · RHS H1b (10–20 °C)

Watch for — Failure to flower: B. socotrana requires cool temperatures (below 15 °C) and shorter day lengths to initiate flowering; if kept too warm or in artificially lit rooms year-round it will produce leaves but no blooms.

What socotra begonia's hardiness rating actually means

Socotra 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 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 10-12 (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 about 10 °C (sustained cold below this is damaging). Socotra Begonia has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Socotra Begonia hardiness — frequently asked questions

Is socotra begonia cold hardy?

Socotra 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. Socotra Begonia can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (indoor in most climates)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature socotra begonia can survive?

What hardiness zone is socotra begonia?

Socotra Begonia is rated USDA 10-12 (indoor in most climates) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can socotra begonia 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 socotra begonia 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.