Repotting guide

When & how to repot Roxburgh's Typhonium (Typhonium roxburghii)

Also called Roxburgh's Rodent Arum, Typhonium.

More about roxburgh's typhonium

About Roxburgh's Typhonium

Typhonium roxburghii · also called Roxburgh's Rodent Arum, Typhonium · tropical

Typhonium roxburghii is a small tuberous aroid from tropical and subtropical Asia, producing arrow-shaped leaves and a slender spathe inflorescence in spring. It is a botanically interesting rather than decorative species, grown by aroid collectors. Contains calcium oxalates common to all Araceae; toxic to pets.

Mature size: 20–35 cm tall in active growth; tubers 1–4 cm in diameter

Watch for — Failure to emerge in spring: Tubers need a minimum soil temperature of around 18°C to break dormancy reliably. Bring pots indoors or into a heated greenhouse if spring temperatures are slow to warm.

How to tell roxburgh's typhonium needs repotting

Repotting on a calendar is less reliable than reading the plant. For roxburgh's typhonium, 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 roxburgh's typhonium 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 roxburgh's typhonium

Lift and divide every 3–4 years once clumps congest. Rather than a true repot, roxburgh's typhonium is lifted and divided once the clump congests and flowering drops off. Small tuberous perennial with seasonal dormancy; produces a slender hooded spathe before or with the foliage.

What size pot to step roxburgh's typhonium up to

Pot size matters less than depth and spacing here. When you replant roxburgh's typhonium, 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 roxburgh's typhonium

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 roxburgh's typhonium in full growth or flower sets it back badly.

Step-by-step: repotting roxburgh's typhonium

Wait for dormancy. Let roxburgh's typhonium 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 free-draining loam-based compost with added grit 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 roxburgh's typhonium, 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 roxburgh's typhonium

Roxburgh's Typhonium wants free-draining loam-based compost with added grit. Use a lean, free-draining compost (John Innes No.2 or equivalent) with 25–30% added horticultural grit or perlite. Good drainage during the dormant period is essential to prevent tuber 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 roxburgh's typhonium — frequently asked questions

How often should you repot roxburgh's typhonium?

Lift and divide every 3–4 years once clumps congest for roxburgh's typhonium. Roxburgh's Typhonium 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 free-draining loam-based compost with added grit. Crowding, not pot size, is what reduces flowering over time.

What size pot does roxburgh's typhonium need?

When is the best time of year to repot roxburgh's typhonium?

Do you "repot" roxburgh's typhonium, or lift and divide it?

You lift and divide it. Roxburgh's Typhonium 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 roxburgh's typhonium after repotting?

Hold off feeding roxburgh's typhonium 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.