I have a bay tree in a pot, the leaves have turned almost dirty looking & I’ve been told it has black rot?? Is there any cure to bring its leaves back to full colour?
1 Answers
The black sooty mass on the leaf surfaces is casued by a sooty mould growing on the honeydew released by either scale insects or greenflies, usually the former.
Spray thoroughly with a general insecticide. Do not use the leaves. The dirty leaves will eventually shed the dirt or fall off.