Repotting guide

When & how to repot Alocasia (Alocasia macrorrhiza)

Also called elephant ear, African mask, giant taro.

About Alocasia

Alocasia macrorrhiza · also called elephant ear, African mask · tropical

Alocasia is a tropical aroid from Southeast Asia grown for its dramatic arrow-shaped leaves. It is a demanding houseplant that needs warmth, humidity, and steady care — and goes dormant in winter, dropping leaves alarmingly until spring. Toxic to pets.

Alocasia is a genus of roughly 70 aroid species originating in tropical Southeast Asia, where the large-leaved 'elephant ears' grow in warm, humid forest conditions.

Use a chunky, free-draining aroid mix; the plant grows from a thick water-storing rhizome or tuber that must never sit in compacted, saturated soil.

Mature size: 60-150 cm tall indoors

Sources: aspca.org, rhs.org.uk, poison.org

How to tell alocasia needs repotting

Repotting on a calendar is less reliable than reading the plant. For alocasia, watch for these signs:

Roots poking out of the drainage holes or coiling visibly around the inside of the pot.
You are watering far more often than you used to because the rootball dries out within a day or two.
Water runs straight through and out the bottom without soaking in.
Top growth has slowed or new alocasia leaves are noticeably smaller than older ones despite good light.

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 alocasia

Every 12–18 months — sooner if roots show fast. Alocasia's growth habit — corm-forming clumping evergreen — sets the pace. Alocasia is a tropical aroid from Southeast Asia grown for its dramatic arrow-shaped leaves. It is a demanding houseplant that needs warmth, humidity, and steady care — and goes dormant in winter, dropping leaves alarmingly until spring. Toxic to pets.

What size pot to step alocasia up to

Step up one pot size — about 2–3 cm (an inch) wider. Alocasia grows fast, so it will fill that space within a season, but jumping several sizes at once still backfires: the unused soil stays soggy and rots even a vigorous root system. One size at a time, every year or so, is the rhythm.

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 alocasia

Early spring, just as new growth restarts, is the ideal window for alocasia. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting alocasia

Time it for spring. Repot alocasia in early spring as growth restarts so it re-roots quickly into the fresh soil.
Choose one size up. Pick a pot about 2–3 cm wider with drainage holes. One step only — a much bigger pot stays soggy and rots roots.
Ease the plant out. Water lightly the day before, then tip alocasia out and gently loosen any roots circling the bottom of the rootball.
Repot at the same depth. Put a layer of fresh chunky aroid mix in the new pot, set the plant so its soil line is unchanged, and backfill, firming lightly.
Water and pause feeding. Water once to settle the soil. Hold off fertiliser for about a month — fresh mix already has nutrients and feeding now burns new roots.

Aftercare

Water alocasia once to settle the soil, then let the surface dry before watering again — fresh mix around the roots stays wetter than the old compacted ball, so the commonest post-repot mistake is overwatering. Keep it out of direct sun for a week or two while roots re-establish. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for alocasia

Alocasia wants chunky aroid mix. Standard potting compost with orchid bark and perlite. Drainage is critical — soggy soil causes corm 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 alocasia — frequently asked questions

How often should you repot alocasia?

Every 12–18 months — sooner if roots show fast for alocasia. Repot alocasia roughly every 12–18 months, in early spring as growth restarts. It grows fast and circles its pot quickly, so step up one size (about 2–3 cm wider) into fresh chunky aroid mix. Don't jump several sizes — that soggy excess soil is what rots vigorous roots.

What size pot does alocasia need?

When is the best time of year to repot alocasia?

Can you put alocasia straight into a much bigger pot?

No. Even a fast-growing alocasia should only go up one pot size at a time. A vastly oversized pot holds a reservoir of wet soil the roots cannot reach, which stays cold and soggy and rots the roots — the opposite of what you wanted.

Should you fertilise alocasia after repotting?

Not immediately. Wait about 4 weeks after repotting alocasia. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.