Cold hardiness & minimum temperature

Is Carnation of India (Ervatamia coronaria)cold hardy? Hardiness zone & min temp

Also called Carnation of India, Crepe Jasmine, Pinwheel Flower, East India Rosebay.

More about carnation of india

About Carnation of India

Ervatamia coronaria · also called Carnation of India, Crepe Jasmine · tropical

Ervatamia coronaria (syn. Tabernaemontana coronaria, T. divaricata) is a fragrant tropical shrub from South and Southeast Asia bearing waxy, pinwheel-shaped white flowers with a sweet jasmine-like scent. A staple of tropical gardens and temple offerings, it blooms almost continuously in warm climates. In temperate regions it excels as a conservatory specimen. All parts are toxic.

Cold limit: USDA 10-12 · RHS H1b (15-32°C)

Watch for — Leaf yellowing in winter: A combination of low light, cold draught, and overwatering in winter causes yellowing and leaf drop. Move to the brightest frost-free position available, reduce watering, and keep temperatures above 15°C. Some winter defoliation is normal at lower temperatures.

What carnation of india's hardiness rating actually means

Carnation of India 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 10-12 — 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). Carnation of India has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Carnation of India hardiness — frequently asked questions

Is carnation of india cold hardy?

Carnation of India 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. Carnation of India can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature carnation of india can survive?

What hardiness zone is carnation of india?

Carnation of India is rated USDA 10-12 and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can carnation of india 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 carnation of india 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.