Cold hardiness & minimum temperature

Is Double Pinwheel Flower (Tabernaemontana divaricata 'Flore Pleno')cold hardy? Hardiness zone & min temp

Also called Double Pinwheel Flower, Double Crape Jasmine, Crape Gardenia, Fleur d'Amour.

More about double pinwheel flower

About Double Pinwheel Flower

Tabernaemontana divaricata 'Flore Pleno' · also called Double Pinwheel Flower, Double Crape Jasmine · tropical

The showier, double-flowered cultivar of Tabernaemontana divaricata, bearing densely petalled, gardenia-like white blooms up to 4 cm across with an intensely sweet nocturnal fragrance. More compact than the species when grown in full sun. A popular container plant for patios and conservatories in temperate climates.

Cold limit: USDA 9-11 · RHS H1b (15–30°C)

Watch for — Bud drop: Flower buds falling before opening are usually caused by sudden temperature change, low humidity, irregular watering, or moving the plant while buds are forming. Stabilise conditions and keep soil evenly moist once buds appear.

What double pinwheel flower's hardiness rating actually means

Double Pinwheel Flower 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 9-11 — 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). Double Pinwheel Flower has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Double Pinwheel Flower hardiness — frequently asked questions

Is double pinwheel flower cold hardy?

Double Pinwheel Flower 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. Double Pinwheel Flower can only live outside year-round in genuinely frost-free climates (roughly USDA 9-11); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature double pinwheel flower can survive?

What hardiness zone is double pinwheel flower?

Double Pinwheel Flower is rated USDA 9-11 and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can double pinwheel flower 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 double pinwheel flower 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.