Black mold on hollies
Assuming our rainfall is the culprit, my 20 year old Nellie and Jos Stevens hollies’ shrub and tree leaves are black inside new growth. How might I treat? I had pruned back new growth to discover this ghastly mold.
Please send us photos of the whole shrub and infected leaves so we can see what you are dealing with. Some sucking insects like soft scales produce a honeydew as they feed on plant sap which fosters the growth of a black sooty mold.