Cold hardiness & minimum temperature

Is Fukien Tea Bonsai (Carmona retusa)cold hardy? Hardiness zone & min temp

Also called Fukien tea, Philippine tea, Carmona bonsai.

More about fukien tea bonsai

About Fukien Tea Bonsai

Carmona retusa · also called Fukien tea, Philippine tea · houseplant

Fukien tea is a tropical evergreen grown as an indoor bonsai, with small glossy dark leaves dotted with tiny white hairs, year-round white flowers, and red berries. It is more demanding than ficus, needing high light, steady warmth, humidity and careful watering. Sensitive to cold and drying out, it rewards consistent care with delicate flowers and fine ramification.

Cold limit: USDA 10-11 (indoor in most US homes) · RHS H1b (18-30°C)

Watch for — Leaf drop from stress: Drops leaves readily after under- or over-watering, draughts, cold, or low light; stabilise warmth, light and even moisture and avoid moving it frequently.

What fukien tea bonsai's hardiness rating actually means

Fukien Tea Bonsai 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 (indoor in most US homes) — 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). Fukien Tea Bonsai has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for fukien tea bonsai 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 fukien tea bonsai 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 fukien tea bonsai can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Fukien Tea Bonsai hardiness — frequently asked questions

Is fukien tea bonsai cold hardy?

Fukien Tea Bonsai 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. Fukien Tea Bonsai can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (indoor in most US homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature fukien tea bonsai can survive?

What hardiness zone is fukien tea bonsai?

Fukien Tea Bonsai is rated USDA 10-11 (indoor in most US homes) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can fukien tea bonsai 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 fukien tea bonsai 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.