Yellow leaves on the Alocasia: the 7 causes and how to tell them apart
August 22, 2026
“A leaf is turning yellow on me” is the number one query we get. The good news is that the Alocasia gives a fairly readable warning: depending on which leaf yellows, where it starts and how fast, you can almost always tell what's going on. These are the seven causes we see at home, from the most harmless to the most serious.
1. It's the oldest leaf and a new one has just opened: normal
Most Alocasias keep a fixed number of leaves (3-5 in the jewels, a bit more in the large ones). When they open a new one, they often sacrifice the oldest: it yellows entirely, uniformly, slowly, and dries out. If the rest of the plant is firm and there's a new leaf, there's no problem. Cut the leaf when it's completely dry.
2. Overwatering or a drowned root
Yellow that starts on the lowerleaves, spreads quickly to several at once and comes with a soft stem at the base or substrate that smells of damp. It's the most frequent cause and the most dangerous. Take out the plant, look at the roots: healthy ones are white or cream and firm; rotten ones, brown and soft. Cut off the rotten parts, let it dry for a few hours and plant in a fresh, airy mix. What that mix should be like is in the care guide.
3. Lack of water
Leaves that first droop or fold and then yellow along the edges, with the substrate dry and pulled away from the pot wall. It recovers within hours after a thorough watering. If it happens often, the pot is too small or the substrate repels water (it happens with very dry coco coir: water it by immersion).
4. Too little light
Pale, general yellow, new leaves increasingly smaller and long petioles stretching toward the window. The plant can't keep all its leaves and drops the lower ones. Move it closer to the light or add a grow lamp; the variegated ones suffer sooner, as we explain in variegated Alocasias.
5. Cold or a draught
Yellow that appears suddenly on one or two leaves after a cold night, an open window or winter shipping, sometimes with translucent or “wet” areas. Below 15 °C the Alocasia stops; if there's also moisture at the root, it rots. Keep the plant away from windows and balconies in winter and, if it has suffered, treat it as in Alocasia in winter.
6. Pests
Yellow mottled, in little dots, not uniform, and often on new leaves. With a magnifier on the underside you'll see spider mites (reddish dots, fine webbing) or thrips (silvery streaks and little black dots). Full treatment in Alocasia pests.
7. Lack of nutrients
It's the least frequent at home. Yellow between the veins, which stay green, on old leaves (lack of magnesium or nitrogen) or on new leaves (iron, common with very hard water and high pH). A balanced fertiliser at half dose in season corrects it within 2-3 leaves. If you feed a lot and in winter, the effect is the opposite: burnt tips.
What to do today
- Look at the substrate: soaked or dry? That rules out half the causes.
- Look at which leaf it is: the oldest or a young one?
- Look at the underside in the light: are there dots, streaks or webbing?
- Feel the base of the stem: firm or soft?
- A single yellow leaf isn't an emergency. Two or more at once, yes: check the root that same day.
If the plant is ours and you're not sure, send us a photo of the leaf, of the substrate and of the base of the stem at info@marinasjunglegems.com. With those three photos we can almost always tell.
Texto redactado con ayuda de inteligencia artificial y publicado por el equipo de Marina’s Jungle Gems.
