Sooty mold
A black, wipeable coating that grows on the honeydew of sap-sucking insects.
What you'll see
- A black, soot-like coating on leaves, stems or fruit that wipes or peels off.
- Sticky honeydew on the leaves, or on surfaces under the plant.
- Aphids, scale, mealybugs or whiteflies on the plant, and ants trailing up the stems.
Why it happens
Sooty molds don't infect the plant: they grow on honeydew from sap-sucking insects. A thick coat blocks light and weakens the plant.
How to fix it
- Find and control the insects making the honeydew; the mold fades once the honeydew stops.
- Wipe the leaves with a soft cloth and lukewarm water.
- Keep ants off the plant, because they protect the honeydew makers.
Keep it from coming back
- Check new growth regularly for sap-sucking insects.
- Feed lightly; soft growth draws sap-feeders.
- Keep ants away from your plants.
Read more
Sources
General guidance, not a diagnosis. For valuable, edible or outdoor crops, check with a local extension service or plant expert. Use any product exactly as its label says, and keep children and pets away while it dries.