Cold hardiness & minimum temperature

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

Also called Biriba, Custard Biriba, Wild Sugar Apple, Lemon Meringue Fruit.

More about custard biriba

About Custard Biriba

Rollinia deliciosa · also called Biriba, Custard Biriba · tropical

Custard Biriba is a fast-growing Amazonian fruit tree prized for its custard-sweet, lemon-tinged flesh. It thrives in humid tropical lowlands with fertile, well-drained soil and abundant warmth. Cold-sensitive and demanding of moisture, it is best suited to frost-free gardens or large tropical greenhouses and fruits prolifically within 3–4 years from seed.

Cold limit: USDA 10b–12 · RHS H1a (18–35°C)

Watch for — Cold damage: Even brief temperatures below 5°C (41°F) cause leaf blackening and branch dieback. Protect with horticultural fleece and move potted specimens under cover. Recovery from light frost is possible if the root system is undamaged.

What custard biriba's hardiness rating actually means

Custard 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 10b–12 — 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). Custard Biriba has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Custard Biriba hardiness — frequently asked questions

Is custard biriba cold hardy?

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

What is the minimum temperature custard biriba can survive?

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

What hardiness zone is custard biriba?

Custard Biriba is rated USDA 10b–12 and RHS H1a — Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever.

Can custard 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 custard 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.