Cold hardiness & minimum temperature

Is Biriba (Rollinia mucosa)cold hardy? Hardiness zone & min temp

Also called Biriba, Biribá, Lemon Meringue Fruit, Wild Sweetsop.

More about biriba

About Biriba

Rollinia mucosa · also called Biriba, Biribá · tropical

A fast-growing Annonaceae tree from the humid tropical lowlands of South America, producing large, spiny-skinned fruits with a sweet, lemon-custard flavour. One of the fastest-fruiting of the custard-apple relatives — bearing in 2–3 years from seed. Requires consistently warm, moist conditions and is highly frost-sensitive. Cannot tolerate drought or prolonged dry spells.

Cold limit: USDA 10a–11 · RHS H1a (18–36 °C)

What biriba's hardiness rating actually means

Biriba 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 10a–11 — 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). Biriba has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for biriba 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 biriba 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 biriba can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1a figure above.

Biriba hardiness — frequently asked questions

Is biriba cold hardy?

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

What is the minimum temperature biriba can survive?

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

What hardiness zone is biriba?

Biriba is rated USDA 10a–11 and RHS H1a — Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever.

Can biriba 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 biriba 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.