Cold hardiness & minimum temperature

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

Also called Mistletoe begonia.

More about mistletoe begonia

About Mistletoe Begonia

Begonia loranthoides · also called Mistletoe begonia · tropical

Begonia loranthoides is a trailing-scandent, semi-epiphytic species native to the wet tropical forests of West and Central Africa, including Cameroon, where it was first documented in 1895. It produces long, woody, trailing stems up to 2 m or more bearing fleshy, distinctly asymmetric, narrowly ovate leaves, and is ideally suited to hanging baskets or training up a support post. Good light is essential for this species to bloom freely, and it will tolerate brief periods of gentle direct sun outside the midday hours. Begonia is listed as toxic to cats, dogs, and horses by the ASPCA.

Cold limit: USDA 10-11 (indoor in most climates) · RHS H1b (15–27°C)

What mistletoe begonia's hardiness rating actually means

Mistletoe 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 10-11 (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). Mistletoe Begonia has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Mistletoe Begonia hardiness — frequently asked questions

Is mistletoe begonia cold hardy?

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

What is the minimum temperature mistletoe begonia can survive?

What hardiness zone is mistletoe begonia?

Mistletoe Begonia is rated USDA 10-11 (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 mistletoe 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 mistletoe 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.