Holly Disease/ Bug Infection
Hi. We have a 15m, 3-year old Holly Hedge that is vibrant and growing well but recently most of leaves appear dirty, as a layer of dark, sticky dust. This is only on the surface as you can wash off with water from leaf. Could this be white fly? If so, what do you recommend as a treatment?
Certified GKH Gardening Expert
It sounds like sooty mold, which is a symptom of several kinds of pests that can attack hollies. I recommend treating the plants with neem oil. This will kill any pests on the plant and treat the sooty mold as well. This article will help: