Repotting guide

When & how to repot Giant Taro (Alocasia macrorrhizos)

Also called Giant Elephant Ear, Upright Elephant Ear.

More about giant taro

About Giant Taro

Alocasia macrorrhizos · also called Giant Elephant Ear, Upright Elephant Ear · tropical

Giant Taro is a massive upright Alocasia with glossy, arrow-shaped leaves held skyward on stout stems, reaching several metres in the tropics. It makes a bold architectural statement indoors and out. A fast, hungry, thirsty aroid, it loves warmth, rich soil and high humidity, and demands far more water than most houseplant Alocasias.

Mature size: Outdoors in the tropics 3-5 m tall with leaves up to 1 m long; indoors commonly 1.5-2.5 m with leaves 60-90 cm.

Watch for — Rhizome rot: Cold, waterlogged soil rots the rhizome despite the plant's love of moisture; ensure the pot drains and ease off water in winter.

How to tell giant taro needs repotting

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

Roots spiralling thickly out of the drainage holes or pushing the whole plant up out of the pot.
The pot is so packed that water runs straight through in seconds and barely wets the soil.
It has split a plastic pot, or the rootball is a solid mass with almost no soil left when you slide it out.
Growth and (for giant taro) flowering have clearly stalled despite good light and feeding — but remember this plant likes being snug, so a little crowding alone is not a reason to repot.

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 giant taro

Only every 2–4 years, when genuinely crowded. Giant Taro is one of the plants that genuinely prefers a snug pot — it grows and flowers better with its roots a little restricted, so resist the urge to repot it on schedule. Evergreen rhizomatous upright herbaceous perennial; forms a thick above-ground stem (caudex) over time, holding huge leaves vertically rather than drooping, hence 'upright elephant ear'..

What size pot to step giant taro up to

Go up only one pot size — roughly 2–3 cm (about an inch) wider in diameter, no more. Giant Taro positively prefers a snug pot: it flowers and grows better when the roots are a little restricted. The single biggest repotting mistake here is over-potting — dropping giant taro into a pot two or three sizes up. All that surplus soil holds water the small root system cannot use, stays cold and wet, and rots the roots within weeks. When in doubt, choose the smaller pot.

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 giant taro

Early spring, just as new growth restarts, is the ideal window for giant taro. 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 giant taro

Confirm it actually needs it. Slide giant taro out and check the roots. Only continue if it is genuinely packed — this plant prefers a snug pot, so if there is still soil and room, put it straight back.
Pick a pot only one size up. Choose a pot just 2–3 cm wider with good drainage. Resist anything bigger; over-potting is the main killer here.
Ease it out gently. Water lightly the day before, then tip giant taro out, supporting the base. Tease the outer roots free only enough to stop them circling.
Repot at the same depth. Add a layer of fresh rich, moisture-retentive but draining mix, set the plant so the soil line sits exactly where it did before, and backfill around the sides, firming lightly.
Settle it in. Water once to settle the soil, then let it sit. Hold off on more water until the top of the soil dries — fresh soil around a small root system stays wet for a while.

Aftercare

Because the new soil holds more water than the old crammed rootball did, ease right back on watering — let the top of the soil dry before you water giant taro again, or you will rot the roots in the very pot you just moved it to. Keep it out of harsh direct sun for a fortnight. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for giant taro

Giant Taro wants rich, moisture-retentive but draining mix. Use a fertile, organic-rich potting mix with added perlite and bark so it holds moisture yet still drains. Unlike most Alocasias it tolerates heavier, water-retentive soil because of its bog origins, but standing water still rots the rhizome. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting giant taro — frequently asked questions

How often should you repot giant taro?

Only every 2–4 years, when genuinely crowded for giant taro. Only repot giant taro every 2–4 years, and only when it is genuinely root-bound — it flowers and grows best slightly crowded. Step up just one pot size in spring using rich, moisture-retentive but draining mix. The key mistake is over-potting: a too-big pot stays wet and rots the roots.

What size pot does giant taro need?

When is the best time of year to repot giant taro?

Does giant taro like to be root-bound?

Yes — giant taro genuinely flowers and grows best when slightly pot-bound, so do not rush to repot it. The mistake to avoid is over-potting into a much larger pot: the excess soil stays wet, the roots cannot use it, and the plant rots. Only repot every few years and only one snug size up.

Should you fertilise giant taro after repotting?

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