John F Murphy asked 15 years ago
What is the cause and how do I prevent a black scum that has appeared on the leaves of a Bay tree?. I can remove it by firmly wiping it off with my finger.
1 Answers
Gerry Daly Staff answered 6 years ago
This is a black fungus growing on the sugar droplets released by scale insects or greenlfies on the leaves. Spray thoroughly with an insecticide such as liquid Derris.
More at: https://gardenie.wpengine.com/gerrycategory/ants/?id=5508
