Cold hardiness & minimum temperature

Is Welwitsch's Anchomanes (Anchomanes welwitschii)cold hardy? Hardiness zone & min temp

Also called Welwitsch's Anchomanes, African Anchomanes.

More about welwitsch's anchomanes

About Welwitsch's Anchomanes

Anchomanes welwitschii · also called Welwitsch's Anchomanes, African Anchomanes · tropical

Anchomanes welwitschii is a dramatic West and Central African tuberous aroid producing a single, large compound leaf on a spiny petiole that can reach over a metre in height. Suited to warm, humid tropical conditions with a pronounced dry-season dormancy. Rarely cultivated outside specialist collections, it demands humus-rich soil, warm temperatures, and ample indirect light.

Cold limit: USDA 11–12 · RHS H1a (18–30°C)

Watch for — Tuber rot during dormancy: The most common failure point. If the tuber is kept moist or cold when dormant, it quickly rots. Lift the tuber after the leaf dies back, allow to dry briefly, then store in barely moist coir at 18–22°C until signs of new growth appear.

What welwitsch's anchomanes's hardiness rating actually means

Welwitsch's Anchomanes 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 H1a means: Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever. On the US scale that maps to USDA 11–12 — 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 above about 15 °C (warm, never cold). Welwitsch's Anchomanes has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for welwitsch's anchomanes as it gets too cold:

Below about above about 15 °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 welwitsch's anchomanes go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above above 15 °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 welwitsch's anchomanes can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1a figure above.

Welwitsch's Anchomanes hardiness — frequently asked questions

Is welwitsch's anchomanes cold hardy?

Welwitsch's Anchomanes 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. Welwitsch's Anchomanes can only live outside year-round in genuinely frost-free climates (roughly USDA 11–12); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature welwitsch's anchomanes can survive?

Minimum survivable temperature is roughly above about 15 °C (warm, never cold). Welwitsch's Anchomanes has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

What hardiness zone is welwitsch's anchomanes?

Welwitsch's Anchomanes is rated USDA 11–12 and RHS H1a — Tropical — needs a heated room or greenhouse; no frost tolerance whatsoever.

Can welwitsch's anchomanes survive winter outside?

It can holiday outdoors in summer once nights are reliably above above 15 °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 welwitsch's anchomanes below its minimum temperature?

Below about above about 15 °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.