Cold hardiness & minimum temperature

Is Naranjilla (Solanum quitoense)cold hardy? Hardiness zone & min temp

Also called Naranjilla, Lulo, Little orange.

More about naranjilla

About Naranjilla

Solanum quitoense · also called Naranjilla, Lulo · tropical

Naranjilla is a striking Andean nightshade shrub with huge purple-veined felted leaves and round orange fruit yielding tangy green pulp used in juices. It favours cool, humid highland conditions, dappled light and protection from intense heat and frost. Spiny forms exist; as a nightshade its leaves and unripe fruit contain solanine and are not edible.

Cold limit: USDA 9-11 (frost-tender; grown as annual or under cover in cooler zones) · RHS H1c (15-25°C)

What naranjilla's hardiness rating actually means

Naranjilla 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 H1c means: Warm-temperate — can summer outdoors but must come in well before the first frost. On the US scale that maps to USDA 9-11 (frost-tender; grown as annual or under cover in cooler zones) — 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 5 °C (and never frost). Naranjilla has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for naranjilla as it gets too cold:

Below about about 5 °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 naranjilla go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 5 °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 naranjilla can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Naranjilla hardiness — frequently asked questions

Is naranjilla cold hardy?

Naranjilla 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. Naranjilla can only live outside year-round in genuinely frost-free climates (roughly USDA 9-11 (frost-tender; grown as annual or under cover in cooler zones)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature naranjilla can survive?

Minimum survivable temperature is roughly about 5 °C (and never frost). Naranjilla has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is naranjilla?

Naranjilla is rated USDA 9-11 (frost-tender; grown as annual or under cover in cooler zones) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can naranjilla survive winter outside?

It can holiday outdoors in summer once nights are reliably above 5 °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 naranjilla below its minimum temperature?

Below about about 5 °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.