Repotting guide

When & how to repot Typhonium trilobatum (Typhonium trilobatum)

Also called three-lobed typhonium, cobra lily.

More about typhonium trilobatum

About Typhonium trilobatum

Typhonium trilobatum · also called three-lobed typhonium, cobra lily · tropical

Typhonium trilobatum is a small tropical Asian aroid grown from a subglobose tuber, with three-lobed arrow-shaped leaves and a dark maroon-purple spathe over a slender spadix that emits a brief carrion odour at bloom. It thrives in warm, humid, humus-rich, well-drained conditions in partial shade and is dormant in cool dry spells.

Mature size: Roughly 45-60 cm tall and 30-45 cm wide; tuber subglobose, around 5 cm across.

How to tell typhonium trilobatum needs repotting

Repotting on a calendar is less reliable than reading the plant. For typhonium trilobatum, 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 typhonium trilobatum 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 typhonium trilobatum

Lift and divide every 3–4 years once clumps congest. Rather than a true repot, typhonium trilobatum is lifted and divided once the clump congests and flowering drops off. Small tuberous tropical aroid with three-lobed, arrow-shaped leaves rising from a subglobose tuber and a dark spathe-and-spadix inflorescence. Goes dormant in cool or dry conditions, regrowing from the tuber..

What size pot to step typhonium trilobatum up to

Pot size matters less than depth and spacing here. When you replant typhonium trilobatum, 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 typhonium trilobatum

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 typhonium trilobatum in full growth or flower sets it back badly.

Step-by-step: repotting typhonium trilobatum

Wait for dormancy. Let typhonium trilobatum 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 humus-rich, well-drained, moisture-retentive 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 typhonium trilobatum, 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 typhonium trilobatum

Typhonium trilobatum wants humus-rich, well-drained, moisture-retentive mix. Fertile loam or potting mix enriched with compost and grit. Neutral to slightly acidic pH. Sharp drainage prevents tuber rot, while the organic content holds the moisture the foliage needs. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting typhonium trilobatum — frequently asked questions

How often should you repot typhonium trilobatum?

Lift and divide every 3–4 years once clumps congest for typhonium trilobatum. Typhonium trilobatum 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 humus-rich, well-drained, moisture-retentive mix. Crowding, not pot size, is what reduces flowering over time.

What size pot does typhonium trilobatum need?

When is the best time of year to repot typhonium trilobatum?

Do you "repot" typhonium trilobatum, or lift and divide it?

You lift and divide it. Typhonium trilobatum 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 typhonium trilobatum after repotting?

Hold off feeding typhonium trilobatum 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.