Cold hardiness & minimum temperature

Is Pulasan (Nephelium ramboutan-ake)cold hardy? Hardiness zone & min temp

Also called Pulasan, Wild Rambutan.

More about pulasan

About Pulasan

Nephelium ramboutan-ake · also called Pulasan, Wild Rambutan · tropical

Pulasan is a prized evergreen fruit tree from the Sapindaceae family, native to lowland rainforests of Malaysia and Indonesia. Its fruits resemble rambutan but the spines are replaced by smooth, stubby tubercles and the flavor is sweeter and richer. Requires a truly humid, lowland tropical climate, consistent rainfall, and full sun to fruit well.

Cold limit: USDA 11–12 · RHS H1a (18–38°C)

What pulasan's hardiness rating actually means

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

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

Pulasan hardiness — frequently asked questions

Is pulasan cold hardy?

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

What is the minimum temperature pulasan can survive?

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

What hardiness zone is pulasan?

Pulasan is rated USDA 11–12 and RHS H1a — Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever.

Can pulasan 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 pulasan 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.