Cold hardiness & minimum temperature

Is Amorphophallus decus-silvae (Amorphophallus decus-silvae)cold hardy? Hardiness zone & min temp

Also called forest pride amorphophallus.

More about amorphophallus decus-silvae

About Amorphophallus decus-silvae

Amorphophallus decus-silvae · also called forest pride amorphophallus · tropical

Amorphophallus decus-silvae is a very large Javan tuberous aroid whose name means 'glory of the forest'. From a massive corm it raises a single, towering, much-divided leaf on a thick mottled petiole before dying back to dormancy. It demands warmth, high humidity, generous space and bright filtered light, making it a prized specimen for greenhouses and serious aroid growers.

Cold limit: USDA 10-12 (indoor or under glass outside the tropics) · RHS H1b (21-32°C)

Watch for — Corm rot: The large corm rots in cold, wet, airless media or if watered during dormancy. Use a deep, gritty, free-draining mix and store the resting corm warm and dryish.

What amorphophallus decus-silvae's hardiness rating actually means

Amorphophallus decus-silvae 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 or under glass outside the tropics) — 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). Amorphophallus decus-silvae has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for amorphophallus decus-silvae 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 amorphophallus decus-silvae 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 amorphophallus decus-silvae can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Amorphophallus decus-silvae hardiness — frequently asked questions

Is amorphophallus decus-silvae cold hardy?

Amorphophallus decus-silvae 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. Amorphophallus decus-silvae can only live outside year-round in genuinely frost-free climates (roughly USDA 10-12 (indoor or under glass outside the tropics)); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature amorphophallus decus-silvae can survive?

What hardiness zone is amorphophallus decus-silvae?

Amorphophallus decus-silvae is rated USDA 10-12 (indoor or under glass outside the tropics) and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can amorphophallus decus-silvae 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 amorphophallus decus-silvae 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.