Cold hardiness & minimum temperature

Is Tamarillo (Solanum betaceum)cold hardy? Hardiness zone & min temp

Also called tamarillo, tree tomato, tomate de árbol.

More about tamarillo

About Tamarillo

Solanum betaceum · also called tamarillo, tree tomato · tropical

Tamarillo is a fast-growing subtropical tree in the nightshade family, bearing egg-shaped red, orange, or yellow fruit with a tangy, tomato-meets-passionfruit flavour. Soft-wooded and shallow-rooted, it crops within two years, thrives in frost-free warmth, and can be containerised and overwintered indoors in cooler climates.

Cold limit: USDA 9b-11 (damaged below about -2°C; grown under cover or as a container plant in colder zones) · RHS H1c (10-27°C)

Watch for — Frost damage: Even a light frost kills foliage and can destroy young plants. Grow in containers to move indoors, or wrap and mulch in marginal climates.

What tamarillo's hardiness rating actually means

Tamarillo 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 9b-11 (damaged below about -2°C; grown under cover or as a container plant in colder 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). Tamarillo has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for tamarillo 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 tamarillo 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 tamarillo can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Tamarillo hardiness — frequently asked questions

Is tamarillo cold hardy?

Tamarillo 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. Tamarillo can only live outside year-round in genuinely frost-free climates (roughly USDA 9b-11 (damaged below about -2°C; grown under cover or as a container plant in colder zones)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature tamarillo can survive?

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

What hardiness zone is tamarillo?

Tamarillo is rated USDA 9b-11 (damaged below about -2°C; grown under cover or as a container plant in colder zones) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can tamarillo 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 tamarillo 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.