Repotting guide

When & how to repot Green Dragon (Arisaema dracontium)

Also called Green Dragon, Dragon Root, Dragon Arum.

More about green dragon

About Green Dragon

Arisaema dracontium · also called Green Dragon, Dragon Root · flowering

Green Dragon is a native North American woodland aroid distinguished by its single leaf divided into 7–15 leaflets and an unusually long spadix protruding dramatically from the green spathe. It naturalises readily in moist, shaded borders and floodplains, tolerating harder winters than most Arisaema. Clusters of bright red berries follow in summer.

Mature size: 30–90 cm tall; leaf canopy 30–60 cm wide

How to tell green dragon needs repotting

Repotting on a calendar is less reliable than reading the plant. For green dragon, 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 green dragon 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 green dragon

Lift and divide every 3–4 years once clumps congest. Rather than a true repot, green dragon is lifted and divided once the clump congests and flowering drops off. Tuberous geophyte; single compound leaf with 7–15 narrow leaflets; fully dormant in winter.

What size pot to step green dragon up to

Pot size matters less than depth and spacing here. When you replant green dragon, 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 green dragon

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 green dragon in full growth or flower sets it back badly.

Step-by-step: repotting green dragon

Wait for dormancy. Let green dragon 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 fertile, humus-rich, moisture-retentive 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 green dragon, 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 green dragon

Green Dragon wants fertile, humus-rich, moisture-retentive loam. A mix of woodland soil amended generously with leaf mold or compost suits this species well. Neutral to slightly acidic pH (5.5–7.0). Unlike many Arisaema, it tolerates heavier soils provided they are not waterlogged year-round. Plant corms 10–15 cm deep. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting green dragon — frequently asked questions

How often should you repot green dragon?

Lift and divide every 3–4 years once clumps congest for green dragon. Green Dragon 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 fertile, humus-rich, moisture-retentive loam. Crowding, not pot size, is what reduces flowering over time.

What size pot does green dragon need?

When is the best time of year to repot green dragon?

Do you "repot" green dragon, or lift and divide it?

You lift and divide it. Green Dragon 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 green dragon after repotting?

Hold off feeding green dragon 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.