Repotting guide

When & how to repot Arisaema griffithii (Arisaema griffithii)

Also called Griffith's cobra lily, Himalayan arisaema.

More about arisaema griffithii

About Arisaema griffithii

Arisaema griffithii · also called Griffith's cobra lily, Himalayan arisaema · flowering

Arisaema griffithii is a dramatic Himalayan woodland tuber prized for its large, hooded green-and-purple spathe netted with paler veins and a long protruding tongue. It emerges in late spring, flowers, then dies back to a dormant tuber by autumn. Grow it in cool, humus-rich, well-drained shade; it resents summer heat and waterlogging.

Mature size: Around 45-60 cm tall and 30-45 cm wide in leaf; spathe to 20 cm long.

How to tell arisaema griffithii needs repotting

Repotting on a calendar is less reliable than reading the plant. For arisaema griffithii, 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 arisaema griffithii 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 arisaema griffithii

Lift and divide every 3–4 years once clumps congest. Rather than a true repot, arisaema griffithii is lifted and divided once the clump congests and flowering drops off. Tuberous herbaceous perennial with a single solar-tracking leaf and a tall, hooded inflorescence (spathe). Fully deciduous, dying back to a dormant underground tuber each year..

What size pot to step arisaema griffithii up to

Pot size matters less than depth and spacing here. When you replant arisaema griffithii, 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 arisaema griffithii

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 arisaema griffithii in full growth or flower sets it back badly.

Step-by-step: repotting arisaema griffithii

Wait for dormancy. Let arisaema griffithii 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, moisture-retentive but free-draining woodland loam 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 arisaema griffithii, 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 arisaema griffithii

Arisaema griffithii wants humus-rich, moisture-retentive but free-draining woodland loam. Blend leaf mould, loam and grit for an open, fertile mix. A slightly acidic to neutral pH suits it. Sharp drainage is essential over winter dormancy or the tuber rots in cold, wet ground. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting arisaema griffithii — frequently asked questions

How often should you repot arisaema griffithii?

Lift and divide every 3–4 years once clumps congest for arisaema griffithii. Arisaema griffithii 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, moisture-retentive but free-draining woodland loam. Crowding, not pot size, is what reduces flowering over time.

What size pot does arisaema griffithii need?

When is the best time of year to repot arisaema griffithii?

Do you "repot" arisaema griffithii, or lift and divide it?

You lift and divide it. Arisaema griffithii 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 arisaema griffithii after repotting?

Hold off feeding arisaema griffithii 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.