Cold hardiness & minimum temperature

Is Cuore di Bue Tomato (Solanum lycopersicum 'Cuore di Bue')cold hardy? Hardiness zone & min temp

Also called Cuore di Bue tomato, ox heart tomato, Italian oxheart.

More about cuore di bue tomato

About Cuore di Bue Tomato

Solanum lycopersicum 'Cuore di Bue' · also called Cuore di Bue tomato, ox heart tomato · edible

Cuore di Bue is a classic Italian oxheart beefsteak with large, ribbed, heart-shaped red fruit, dense low-seed flesh and rich flavour. The indeterminate vines are productive but need firm support for the heavy fruit, plus full sun and a long warm season. Its foliage and unripe fruit are toxic to pets.

Cold limit: USDA Grown as a warm-season annual in all zones · RHS H1c (18-29°C)

What cuore di bue tomato's hardiness rating actually means

Cuore di Bue Tomato 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 Grown as a warm-season annual in all 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). Cuore di Bue Tomato has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Cuore di Bue Tomato hardiness — frequently asked questions

Is cuore di bue tomato cold hardy?

Cuore di Bue Tomato 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. Cuore di Bue Tomato can only live outside year-round in genuinely frost-free climates (roughly USDA Grown as a warm-season annual in all zones); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature cuore di bue tomato can survive?

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

What hardiness zone is cuore di bue tomato?

Cuore di Bue Tomato is rated USDA Grown as a warm-season annual in all zones and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can cuore di bue tomato 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 cuore di bue tomato 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.