Cold hardiness & minimum temperature

Is Anthurium andraeanum 'Rubrum' (Anthurium andraeanum 'Rubrum')cold hardy? Hardiness zone & min temp

Also called red anthurium, Rubrum anthurium.

More about anthurium andraeanum 'rubrum'

About Anthurium andraeanum 'Rubrum'

Anthurium andraeanum 'Rubrum' · also called red anthurium, Rubrum anthurium · tropical

'Rubrum' is the classic deep-red Anthurium andraeanum, grown for its glossy crimson heart-shaped spathes and pale spadix set against dark waxy leaves. An epiphytic rainforest aroid from Colombia, it flowers almost continuously indoors when given bright indirect light, even moisture, warmth, high humidity and a loose, fast-draining aroid mix.

Cold limit: USDA 11-12 (indoor in most US homes) · RHS H1b (18-29°C)

What anthurium andraeanum 'rubrum''s hardiness rating actually means

Anthurium andraeanum 'Rubrum' 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 11-12 (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). Anthurium andraeanum 'Rubrum' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for anthurium andraeanum 'rubrum' 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 anthurium andraeanum 'rubrum' 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 anthurium andraeanum 'rubrum' can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Anthurium andraeanum 'Rubrum' hardiness — frequently asked questions

Is anthurium andraeanum 'rubrum' cold hardy?

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

What is the minimum temperature anthurium andraeanum 'rubrum' can survive?

What hardiness zone is anthurium andraeanum 'rubrum'?

Anthurium andraeanum 'Rubrum' is rated USDA 11-12 (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 anthurium andraeanum 'rubrum' 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 anthurium andraeanum 'rubrum' 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.