Repotting guide

When & how to repot Titan Arum (Amorphophallus titanum)

Also called titan arum, corpse flower, bunga bangkai.

More about titan arum

About Titan Arum

Amorphophallus titanum · also called titan arum, corpse flower · tropical

Amorphophallus titanum, the titan arum or corpse flower, produces one of the largest unbranched inflorescences on Earth, emitting a powerful rotting-flesh odour over a day or two to attract pollinators. Native to Sumatran rainforest, it alternates a single enormous leaf with rare, spectacular blooms. It is a demanding warm, humid, collection plant.

Mature size: Leaf can exceed 4-5 m tall; the inflorescence can top 3 m; corm may weigh 50 kg or more.

How to tell titan arum needs repotting

Repotting on a calendar is less reliable than reading the plant. For titan arum, watch for these signs:

Flowering has tailed off year on year and the clump has become congested and overcrowded.
Lots of leaf and few flowers — a classic sign that titan arum bulbs or tubers need lifting and dividing.
Bulbs visibly bursting the pot or pushing each other to the surface.
It is the natural dormancy window (foliage yellowed and died back) — the only safe time to lift and split.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot titan arum

Lift and divide every 3–4 years once clumps congest. Rather than a true repot, titan arum is lifted and divided once the clump congests and flowering drops off. Giant tuberous aroid that alternates between a single tree-sized divided leaf and, after years of corm-building, a colossal short-lived malodorous inflorescence..

What size pot to step titan arum up to

Pot size matters less than depth and spacing here. When you replant titan arum, set the bulbs or tubers at the correct depth (a rough guide: two to three times their own height of soil over the top) and space them so they are not touching. A wide, shallow pot suits a clump better than a tall narrow one.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot titan arum

The only safe window is dormancy: wait until the foliage has yellowed and died back naturally, lift and divide then, and replant before or at the start of the next growing season. Disturbing titan arum in full growth or flower sets it back badly.

Step-by-step: repotting titan arum

Wait for dormancy. Let titan arum foliage yellow and die back completely. Lifting while it is in growth wastes the energy it is storing for next year.
Lift carefully. Loosen the soil well away from the bulbs/tubers with a fork and ease the whole clump out without spearing them.
Separate the offsets. Gently pull the clump apart into individual bulbs or tubers. Keep only firm, healthy, blemish-free ones.
Replant at the right depth. Reset them in fresh rich, exceptionally free-draining mix at the correct depth and spacing — not touching — so each has room to bulk up.
Water in and rest. Water once to settle them, then keep on the dry side until growth resumes. Do not feed until leaves are actively growing.

Aftercare

After replanting titan arum, keep the soil barely moist — not wet — until shoots appear; bulbs and tubers rot in cold, saturated soil. Once leaves are growing strongly, resume normal watering. Hold off feeding until the plant is in active growth again.

The right soil mix for titan arum

Titan Arum wants rich, exceptionally free-draining mix. Use a deep, fertile, very well-drained medium high in organic matter with plenty of grit, bark, and perlite. The giant corm needs ample room and aeration; standing moisture quickly causes rot. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting titan arum — frequently asked questions

How often should you repot titan arum?

Lift and divide every 3–4 years once clumps congest for titan arum. Titan Arum is lifted and divided, not "repotted". Every 3–4 years, once the foliage has died back and it is dormant, lift the clump, separate the offsets, and replant at the correct depth in rich, exceptionally free-draining mix. Crowding, not pot size, is what reduces flowering over time.

What size pot does titan arum need?

When is the best time of year to repot titan arum?

Do you "repot" titan arum, or lift and divide it?

You lift and divide it. Titan Arum grows from bulbs or tubers, so instead of repotting you wait for dormancy, lift the congested clump, separate the healthy offsets, and replant them at the right depth and spacing. Doing this every 3–4 years restores flowering.

Should you fertilise titan arum after repotting?

Hold off feeding titan arum until it is in active growth again. Fresh soil already carries enough nutrients to get it re-established, and feeding disturbed roots too soon does more harm than good.