Repotting guide

When & how to repot Typhonium venosum (Typhonium venosum)

Also called Voodoo Lily, Devil's Tongue.

More about typhonium venosum

About Typhonium venosum

Typhonium venosum · also called Voodoo Lily, Devil's Tongue · tropical

Typhonium venosum (formerly Sauromatum venosum) is a tuberous aroid famous for a dramatic purple-spotted spathe that emits a strong carrion smell to attract fly pollinators. After flowering, a single umbrella-like, divided leaf unfurls on a mottled stalk. The dormant tuber will even bloom dry on a windowsill, making it a curiosity-grower favourite.

Mature size: The leaf reaches about 30-50 cm tall; the inflorescence can be 20-30 cm long. Tubers enlarge and offset with age.

Watch for — Foul carrion odour: The open spathe smells of rotting meat for a day or two to lure flies; this is normal — ventilate the room or move the pot outside while it blooms.

How to tell typhonium venosum needs repotting

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

Lift and divide every 3–4 years once clumps congest. Rather than a true repot, typhonium venosum is lifted and divided once the clump congests and flowering drops off. Tuberous, dormant-cycling aroid: a single foul-smelling spathe emerges first, then one large, deeply divided umbrella leaf on a spotted petiole. Dies back to a tuber each year and offsets readily..

What size pot to step typhonium venosum up to

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

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 venosum in full growth or flower sets it back badly.

Step-by-step: repotting typhonium venosum

Wait for dormancy. Let typhonium venosum 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, free-draining loamy 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 venosum, 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 venosum

Typhonium venosum wants rich, free-draining loamy mix. Plant in a fertile, humus-rich but well-drained potting mix with added grit or perlite. The tuber rots in cold, wet soil, so sharp drainage during dormancy is essential. 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 venosum — frequently asked questions

How often should you repot typhonium venosum?

Lift and divide every 3–4 years once clumps congest for typhonium venosum. Typhonium venosum 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, free-draining loamy mix. Crowding, not pot size, is what reduces flowering over time.

What size pot does typhonium venosum need?

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

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

You lift and divide it. Typhonium venosum 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 venosum after repotting?

Hold off feeding typhonium venosum 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.