Holly Bush Disease

Question

The huge holly bush in my neighbor’s yard is covered with a white fungus or larvae on the leaves. As this overhangs the fence between us, I am concerned it will drop and infect my plants. The lady gardener says it is not white fly.

Answer 1

Are the areas powdery in nature? If so you are dealing with powdery mildew. Here is an article that you may find helpful: https://www.gardeningknowhow.com/problems/get-the-cure-for-powdery-mildew.htm

If not, it could be scale or mealybugs, both of which could be treated with neem oil (as can powdery mildew). I have found it to be very effective against these pests. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm

For additional information on scale bugs, which commonly affect these plants, here is an article that you may find helpful: https://www.gardeningknowhow.com/plant-problems/pests/scale-bug-how-to-control-plant-scale.htm