Cold hardiness & minimum temperature

Is Ilama (Annona diversifolia)cold hardy? Hardiness zone & min temp

Also called Ilama, Ilamatepec.

More about ilama

About Ilama

Annona diversifolia · also called Ilama, Ilamatepec · tropical

Ilama is a small deciduous tropical tree from Mexico and Central America, prized for its sweet pink or green custard-like fruit. It thrives in hot, dry-to-seasonal lowlands, tolerates poor soils, and needs frost-free warmth. Hand-pollination is often required for good fruit set, and it stays smaller than its soursop and cherimoya relatives.

Cold limit: USDA 10-11 (frost-tender; container/greenhouse in cooler US zones) · RHS H1b (20-32°C)

Watch for — Cold and frost damage: Even a light frost defoliates or kills the tree; protect or move containers indoors when temperatures approach 2-4°C.

What ilama's hardiness rating actually means

Ilama 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 H1b means: Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season. On the US scale that maps to USDA 10-11 (frost-tender; container/greenhouse in cooler US 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 10 °C (sustained cold below this is damaging). Ilama has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for ilama as it gets too cold:

Below about about 10 °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 ilama go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 10 °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 ilama can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Ilama hardiness — frequently asked questions

Is ilama cold hardy?

Ilama 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. Ilama can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (frost-tender; container/greenhouse in cooler US zones)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature ilama can survive?

Minimum survivable temperature is roughly about 10 °C (sustained cold below this is damaging). Ilama has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is ilama?

Ilama is rated USDA 10-11 (frost-tender; container/greenhouse in cooler US zones) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can ilama survive winter outside?

It can holiday outdoors in summer once nights are reliably above 10 °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 ilama below its minimum temperature?

Below about about 10 °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.