Mature size & growth rate

How big does Anchomanes giganteus (Anchomanes giganteus) get?

Also called giant anchomanes, West African arum.

More about anchomanes giganteus

About Anchomanes giganteus

Anchomanes giganteus · also called giant anchomanes, West African arum · tropical

Anchomanes giganteus is a towering tropical African aroid, even more imposing than A. difformis, producing one immense, intricately divided leaf on a tall, spiny, marbled stalk from a massive underground rhizome. A seasonal grower from West and Central African forest, it dies back fully in the dry season. Its sheer scale makes it a dramatic specimen for large warm conservatories.

Mature size: Leaf and petiole frequently exceed 2 m tall, with a wide, deeply divided canopy.

Watch for — Leaf instability: The single tall leaf can flop or break if under-lit or unstaked. Provide bright light and support the petiole if needed.

Indoor size vs how big it gets in the wild

Anchomanes giganteus stays fairly low but widens over time — it spreads into a bigger clump by offsets, runners or rhizomes rather than shooting upward. Indoors and in a pot, expect leaf and petiole frequently exceed 2 m tall, with a wide, deeply divided canopy.. A pot, your light levels and a little pruning are what set the final size in a home, far more than the plant's theoretical potential.

Size here is about width, not height: the plant builds an ever-wider clump or sends out plantlets and runners while staying relatively short.

Growth rate and years to mature

Anchomanes giganteus is a moderate grower. Realistically, expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Its feeding profile backs this up: feed every 2-3 weeks with a balanced liquid fertiliser through active growth to power the enormous leaf, then stop entirely as the plant enters dormancy.

Want this turned into the right next pot at the right moment? The pot size calculator and the anchomanes giganteus repotting guide cover when and how much to size up — pot size is one of the biggest levers on how fast anchomanes giganteus grows.

How to keep anchomanes giganteus smaller

You are not stuck with the maximum size. For anchomanes giganteus specifically, these are the levers, in order of impact:

Divide the clump every year or two — splitting anchomanes giganteus is the main way to control its spread and refresh it.
Remove runners, plantlets or offsets as they appear if you want it to stay a single tight clump.
Keep it slightly pot-bound; a snug pot naturally limits how wide the clump can get.

The keep-it-smaller method, step by step

Lift the whole plant. Slide anchomanes giganteus out of its pot in spring when the clump has filled it.
Split the clump. Tease or cut the rootball into two or more sections, each with healthy roots and growth.
Repot one division. Put a single division back in the original pot to reset it to a smaller size; pot or give away the rest.
Remove offsets as they form. Through the year, detach new runners or pups to stop it spreading again.

How to grow anchomanes giganteus bigger or faster

If you want it to fill the space sooner, push the conditions rather than hoping — for anchomanes giganteus the accelerators are:

Give it a wider pot and let the clump fill it — width is exactly how this plant gets bigger.
Good light plus regular feeding maximises offset and runner production.
Leave plantlets and offsets attached and feed through the growing season for the fastest spread.

Light is almost always the ceiling. The anchomanes giganteus light requirements page covers exactly how bright a spot it needs to grow at its potential instead of stalling.

When anchomanes giganteus outgrows the room (or the pot)

"Too big" usually arrives as one of these signs for anchomanes giganteus:

The clump bulging over the pot rim or splitting the pot — the cue to divide, not to find a bigger room.
A dense centre that goes bare or tired while the edges keep spreading.
Runners or offsets escaping across the shelf or into neighbouring pots.

If it is the pot rather than the room, it is a repotting job, not a goodbye — see the anchomanes giganteus repotting guide. If you want more of this plant instead of a bigger one, the anchomanes giganteus propagation guide turns prunings into new plants.

Anchomanes giganteus size — frequently asked questions

How big does anchomanes giganteus get?

Anchomanes giganteus reaches leaf and petiole frequently exceed 2 m tall, with a wide, deeply divided canopy. when grown indoors. Size here is about width, not height: the plant builds an ever-wider clump or sends out plantlets and runners while staying relatively short.

Is anchomanes giganteus slow or fast growing?

Anchomanes giganteus is a moderate grower. Expect three to six years to reach mature indoor size, gaining a steady amount each growing season. Anchomanes giganteus stays fairly low but widens over time — it spreads into a bigger clump by offsets, runners or rhizomes rather than shooting upward.

How long does anchomanes giganteus take to reach full size?

Roughly three to six years to reach mature indoor size, gaining a steady amount each growing season. Light, pot size and feeding move that timeline more than anything else.

How do I keep anchomanes giganteus smaller?

Divide the clump every year or two — splitting anchomanes giganteus is the main way to control its spread and refresh it. Remove runners, plantlets or offsets as they appear if you want it to stay a single tight clump. Keep it slightly pot-bound; a snug pot naturally limits how wide the clump can get.

How can I make anchomanes giganteus grow bigger or faster?

Give it a wider pot and let the clump fill it — width is exactly how this plant gets bigger. Good light plus regular feeding maximises offset and runner production. Leave plantlets and offsets attached and feed through the growing season for the fastest spread.