Why are my Alocasia (African mask) leaves getting yellow and brown patches?

What's likely going on

From the photo, the leaf has:

• Brown, dry patches between the veins
• A yellow “halo” around those patches
• Some edge yellowing and crisping

That pattern is typical of leaf tissue that has been damaged and then dried out, not a pest. On Alocasia, this usually comes from one or a mix of:

1. Watering and root stress – Soil staying wet for a long time (or swinging from very dry to very wet) can damage roots. Damaged roots can’t supply water evenly, so parts of the leaf die off in patches.
2. Light or temperature shock – Direct hot sun, or a cold draft, can scorch sections of an Alocasia leaf, which later turn brown with yellow edges.
3. Fertilizer or mineral buildup – If fertilizer is strong or salts accumulate in the pot, the leaf tips and patches can burn similarly.

The photo doesn’t clearly show the potting mix or drainage holes, so to be sure, it helps to check the roots and soil condition.

What to do

1. Check the soil and roots
   Gently slide the plant from its pot. Roots should be firm and light-colored. Trim any mushy, black, or foul-smelling roots, and repot in a loose, well‑draining mix (potting soil + perlite or coco chips).

2. Adjust watering
   Water only when the top 2–3 cm of soil feels dry. Water thoroughly, then empty any saucer so the pot isn’t sitting in water.

3. Fix the light
   Keep it in bright, indirect light. Move it back from harsh window sun or use a sheer curtain. Avoid cold drafts from AC or open windows at night.

4. Rinse out excess fertilizer
   If you fertilize often, run plenty of water through the pot once to flush salts. In future, feed lightly (about half strength) only in the growing season.

5. Increase humidity
   Alocasias like moist air. Group with other plants, use a pebble tray, or a humidifier if the air is very dry.

6. Remove worst leaves
   Once new growth looks healthy, you can cut off badly damaged leaves at the base. They won’t recover.

How to prevent it

• Keep a steady watering rhythm: consistently slightly moist, never soggy.
• Use a pot with drainage holes and airy mix.
• Protect from direct midday sun and sudden temperature swings.
• Fertilize sparingly and flush the soil a couple of times a year.
• Keep humidity moderate to high around the plant.

When to worry

• New leaves come out deformed, very small, or already spotted.
• Multiple leaves yellow and die in quick succession.
• The stem base or soil smells sour, and roots are mostly black or mushy.

If you see those signs, treat it as root rot (trim roots, fresh mix, smaller pot, careful watering). Otherwise, with gentler conditions, new leaves should grow in looking much better.