Cold hardiness & minimum temperature

Is Angraecum eburneum (Angraecum eburneum)cold hardy? Hardiness zone & min temp

Also called Ivory Angraecum, Ivory Star Orchid.

More about angraecum eburneum

About Angraecum eburneum

Angraecum eburneum · also called Ivory Angraecum, Ivory Star Orchid · tropical

Angraecum eburneum is a large, robust monopodial orchid from Madagascar and nearby islands, growing strap-leaved fans over a metre tall and bearing waxy green-and-ivory star flowers with a long nectar spur. It loves strong light, warmth, and year-round watering with no true rest. A statement plant for warm, bright spaces.

Cold limit: USDA 11-12 (indoor or greenhouse in most US homes) · RHS H1a (16-30°C)

Watch for — No flowers despite healthy growth: Often too little light or no day-to-night temperature drop. Increase light and give a roughly 10°C cooler night in autumn to initiate spikes.

What angraecum eburneum's hardiness rating actually means

Angraecum eburneum 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 H1a means: Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever. On the US scale that maps to USDA 11-12 (indoor or greenhouse 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 above about 15 °C (warm, never cold). Angraecum eburneum has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for angraecum eburneum as it gets too cold:

Below about above about 15 °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 angraecum eburneum go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above above 15 °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 angraecum eburneum can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1a figure above.

Angraecum eburneum hardiness — frequently asked questions

Is angraecum eburneum cold hardy?

Angraecum eburneum 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. Angraecum eburneum can only live outside year-round in genuinely frost-free climates (roughly USDA 11-12 (indoor or greenhouse in most US homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature angraecum eburneum can survive?

Minimum survivable temperature is roughly above about 15 °C (warm, never cold). Angraecum eburneum has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is angraecum eburneum?

Angraecum eburneum is rated USDA 11-12 (indoor or greenhouse in most US homes) and RHS H1a — Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever.

Can angraecum eburneum survive winter outside?

It can holiday outdoors in summer once nights are reliably above above 15 °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 angraecum eburneum below its minimum temperature?

Below about above about 15 °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.