Alocasia
Dramatic arrow-shaped leaves with bold white veins, on a plant that goes dormant when it is unhappy and comes back when it is not. Beautiful, a little moody, and it wants warmth and humidity.
Alocasia is the plant that looks like it came from a rainforest, because it did. The African mask types like Polly have glossy, deeply veined leaves that stop people in their tracks. The big elephant ears can reach the ceiling.
It has one habit worth knowing: when it gets too cold, too dry or too dark, it drops its leaves and goes dormant. It is not dead. Keep the corm barely moist and it comes back.
Light
Bright indirect light. An east window, or a few feet from a south one. It tolerates medium light with smaller leaves. Direct sun scorches the leaves quickly.
Water
Lightly moist in the growing season: water when the top inch or two is dry, about every six days in summer. In winter, when growth stops, let it dry further between waterings, every twelve days or so. It rots if kept wet in the cold months and drops leaves if kept dry in the warm ones.
Soil and potting
An airy, chunky mix: potting soil with orchid bark and perlite. Repot every eighteen months in spring, one size up. Baby corms in the soil can be potted separately.
Feeding
A half-strength balanced feed monthly in spring and summer. It is a hungry grower in warm weather.
Propagation
Division of the corms at repotting. The small bulb-like corms in the soil can be set in damp sphagnum in a warm spot and will sprout in a few weeks.
In a hot, dry home
It needs humidity above fifty percent, which is the hard part here. A humidifier or a bathroom window spot from May to September, away from every vent. It also drops leaves when the AC makes a room cold at night; keep it in the warmest room you have. Expect a winter dormancy and do not panic.
Alocasia varieties
Same care, different look. These are the named forms you will see for sale.
-
The dark, white-veined mask-shaped one. Has its own profile.
Full profile -
Silver scaled leaves. Has its own profile.
Full profile -
Dark green scaled leaves. Has its own profile.
Full profile -
Velvety near-black leaves with silver veins. Has its own profile.
Full profile -
Velvety green leaves with white veins. Has its own profile.
Full profile - Scalprum
Narrow, metallic blue-green leaves with a raised texture.
- Red Secret
Copper-red metallic leaves.
- Ebony
Alocasia wentii: dark green leaves with bronze-purple undersides. Tougher than most.
- Mickey Mouse
Xanthosoma Variegated Monstrosum: white-splashed, oddly shaped leaves. A different genus, same care.
Problems and fixes
Leaves yellowing and dropping one by one
Likely cause: Going dormant from cold, dark or dry conditions
Fix: Keep the pot barely moist and warm. New leaves emerge when conditions improve.
Brown, crispy leaf edges
Likely cause: Low humidity
Fix: Raise humidity with a humidifier or grouping; move away from vents.
Fine webbing under leaves
Likely cause: Spider mites, which thrive in dry air
Fix: Shower the plant, treat with insecticidal soap, raise humidity.
Water droplets on leaf tips
Likely cause: Guttation, normal after watering
Fix: Nothing. It is the plant releasing excess water.
Alocasia questions
Is alocasia toxic to cats and dogs?
Yes. It contains calcium oxalate crystals that cause painful mouth irritation. Keep it out of reach.
Why is my alocasia dropping all its leaves?
It is going dormant, usually because of cold, low light or dry soil in winter. Keep the corm warm and barely moist and it will regrow in spring.
How much humidity does alocasia need?
Fifty percent or more. In a dry home that means a humidifier or a bathroom spot, grouped with other plants.
