Cold hardiness & minimum temperature

Is Aglaonema 'Siam Aurora' (Red Chinese Evergreen) (Aglaonema 'Siam Aurora')cold hardy? Hardiness zone & min temp

Also called Red Aglaonema, Red Chinese Evergreen, Siam Aurora, Aglaonema Siam.

More about aglaonema 'siam aurora' (red chinese evergreen)

About Aglaonema 'Siam Aurora' (Red Chinese Evergreen)

Aglaonema 'Siam Aurora' · also called Red Aglaonema, Red Chinese Evergreen · houseplant

Aglaonema 'Siam Aurora' is a striking red-and-green Chinese evergreen prized as a low-maintenance foliage houseplant. Give it medium, indirect light to keep its pink-red variegation vivid, water when the top inch dries, and keep it warm (18-27C). Note: the ASPCA lists Aglaonema as toxic to cats and dogs, so keep it out of reach.

Cold limit: USDA 10-11 (grown as a houseplant in cooler zones) (18-27C)

Watch for — Drooping and curling from cold: Temperatures below 13-15C (55-59F) and cold drafts cause wilting, curling and dark patches. Keep it away from windows, doors and AC vents in winter and maintain 18-27C.

What aglaonema 'siam aurora' (red chinese evergreen)'s hardiness rating actually means

Aglaonema 'Siam Aurora' (Red Chinese Evergreen) 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 H1c means: Warm-temperate — can summer outdoors but must come in well before the first frost. On the US scale that maps to USDA 10-11 (grown as a houseplant in cooler zones) — 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 5 °C (and never frost). Aglaonema 'Siam Aurora' (Red Chinese Evergreen) has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for aglaonema 'siam aurora' (red chinese evergreen) as it gets too cold:

Below about about 5 °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 aglaonema 'siam aurora' (red chinese evergreen) go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 5 °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 aglaonema 'siam aurora' (red chinese evergreen) can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1c figure above.

Aglaonema 'Siam Aurora' (Red Chinese Evergreen) hardiness — frequently asked questions

Is aglaonema 'siam aurora' (red chinese evergreen) cold hardy?

Aglaonema 'Siam Aurora' (Red Chinese Evergreen) 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. Aglaonema 'Siam Aurora' (Red Chinese Evergreen) can only live outside year-round in genuinely frost-free climates (roughly USDA 10-11 (grown as a houseplant in cooler zones)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature aglaonema 'siam aurora' (red chinese evergreen) can survive?

What hardiness zone is aglaonema 'siam aurora' (red chinese evergreen)?

Aglaonema 'Siam Aurora' (Red Chinese Evergreen) is rated USDA 10-11 (grown as a houseplant in cooler zones) and RHS H1c — Warm-temperate — can summer outdoors but must come in well before the first frost.

Can aglaonema 'siam aurora' (red chinese evergreen) survive winter outside?

It can holiday outdoors in summer once nights are reliably above 5 °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 aglaonema 'siam aurora' (red chinese evergreen) below its minimum temperature?

Below about about 5 °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.