Cold hardiness & minimum temperature

Is Aglaonema White Rajah (Aglaonema 'White Rajah')cold hardy? Hardiness zone & min temp

Also called White Rajah Chinese Evergreen.

More about aglaonema white rajah

About Aglaonema White Rajah

Aglaonema 'White Rajah' · also called White Rajah Chinese Evergreen · houseplant

Aglaonema 'White Rajah' is a striking Chinese evergreen cultivar with creamy-white to silver leaves edged and veined in green. It is an easygoing, slow-growing houseplant that tolerates lower light better than most variegated foliage, though its pale leaves prefer bright-indirect light. Keep it warm and avoid overwatering for trouble-free growth.

Cold limit: USDA 10-12 (indoor in most US homes) · RHS H1b (18-27°C)

Watch for — Cold damage: Greyish, water-soaked blotches appear below about 15°C. Keep it warm, away from cold windows, drafts and air-conditioning vents, which it strongly dislikes.

What aglaonema white rajah's hardiness rating actually means

Aglaonema White Rajah 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 (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). Aglaonema White Rajah has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Aglaonema White Rajah hardiness — frequently asked questions

Is aglaonema white rajah cold hardy?

Aglaonema White Rajah 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 White Rajah can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (indoor in most US homes)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature aglaonema white rajah can survive?

What hardiness zone is aglaonema white rajah?

Aglaonema White Rajah is rated USDA 10-12 (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 aglaonema white rajah 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 aglaonema white rajah 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.