Cold hardiness & minimum temperature

Is Aglaonema 'First Diamond' (Aglaonema commutatum 'First Diamond')cold hardy? Hardiness zone & min temp

Also called First Diamond Chinese Evergreen.

More about aglaonema 'first diamond'

About Aglaonema 'First Diamond'

Aglaonema commutatum 'First Diamond' · also called First Diamond Chinese Evergreen · houseplant

Aglaonema 'First Diamond' is a compact Chinese Evergreen with near-white, silvery leaves edged and flecked in green. It thrives in low-to-medium light, tolerates neglect, and is among the easiest variegated aroids. The pale foliage burns in direct sun, so keep it shaded. Warm, draught-free rooms with steady moisture keep its bright colouring crisp.

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

Watch for — Yellowing lower leaves: Most often overwatering or cold, soggy soil. Let the top third of the mix dry and check drainage.

What aglaonema 'first diamond''s hardiness rating actually means

Aglaonema 'First Diamond' 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 'First Diamond' has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

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

Aglaonema 'First Diamond' hardiness — frequently asked questions

Is aglaonema 'first diamond' cold hardy?

Aglaonema 'First Diamond' 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 'First Diamond' 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 'first diamond' can survive?

What hardiness zone is aglaonema 'first diamond'?

Aglaonema 'First Diamond' 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 'first diamond' 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 'first diamond' 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.