Appearance

Araceae

Alocasia

Grown on a thick underground stem — a rhizome, though the hobby calls its offsets corms — and one of only two genera here that go properly dormant rather than merely slowing down; the Indian kale is the other. Most of the reputation for being difficult comes from underwaterings or people treating a resting plant as a dead one.

Native to Tropical and subtropical Asia to eastern Australia

Species

Alocasia azlanii

Red jewel alocasia

2 photographs

Alocasia baginda 'Dragon Scale'

Dragon Scale

2 photographs

Alocasia micholitziana 'Frydek'

Frydek variegata

13 photographs

Alocasia nebula

Nebula

2 photographs

How Alocasia generally wants to be treated

Plant care

Species pages start from this and record only where they differ.

Light
Bright indirect, and more of it than most people give them. They will not tolerate direct midday sun, but too little light produces weak petioles that cannot hold the leaves up.
Water
Water once the top few centimetres have dried through the growing season, and cut back sharply in dormancy — overwatering a resting plant is the main route to rot. Never waterlogged, never bone dry.
Humidity
Medium to high. Dry air browns the leaves and, more reliably than anything else, brings spider mites.
Temperature
64-84 °F (18-29 °C) in growth, and not below about 61 °F (16 °C) while growing. Winter floor 50 °F (10 °C): below that, or in cooler and drier conditions generally, they drop leaves and rest, which is normal rather than fatal.
Substrate
Airy but moisture-retentive — bark and perlite with enough coir or sphagnum that it does not dry out in a day.
Fertilizer
A balanced feed at half strength every third watering through spring and summer. Nothing at all once growth stops.
Propagation
Offsets and the small tubers that form on the rhizome, separated at repotting. They root in damp sphagnum in a closed container.
Dormancy
Expected in a cool, dark winter — though a plant kept warm and bright may stay evergreen. It drops leaves and rests on the rhizome. Keep the mix barely damp, stop feeding, and do not repot; most losses happen when a resting plant is treated as a sick one.
Common problems
  • Sudden leaf loss in autumn is usually dormancy, not death — check the rhizome before discarding anything
  • Spider mites are the defining pest of this genus; inspect leaf undersides weekly in dry air
  • Drooping petioles that do not recover after watering usually mean rot below the soil
  • Guttation — water beading at the leaf edge — is normal and not a symptom
  • Every part carries calcium oxalate crystals: painful if eaten, and an irritant to skin and eyes

Sources 12345

In the collection