I noticed that our one holly bush has a noticeable number of dead leaves on some of the branches. The dead leaves also have tiny white blotches on them, almost like dried foam. The rest of the bush is beautiful and hopefully healthy. I'd like to know if there is something I can do to safeguard the rest of the healthy leaves and branches.
Holly Disease or Pest
Certified GKH Gardening Expert
Are the spots powdery in nature. If so, it is is powdery mildew and can be treated with neem oil. Here is more info: https://www.gardeningknowhow.com/problems/get-the-cure-for-powdery-mildew.htm https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm
In addition, it could be scale or mealybugs, which can also be treated with neem oil. These articles should help: https://www.gardeningknowhow.com/plant-problems/pests/scale-bug-how-to-control-plant-scale.htm