White powder on holly branches

Question

There is white powdery stuff growing up the branches on my holly. Is this a fungus?

Answer 1

Yes, this is most likely a fungus called powdery mildew. It is common and can affect holly shrubs, but will typically not seriously harm them. A spray of whole milk diluted in water has been shown to help kill powdery mildew fungus. These articles discuss other ways to treat and prevent powdery mildew:

https://www.gardeningknowhow.com/plant-problems/disease/powdery-mildew-homemade-and-organic-remedies.htm
https://www.gardeningknowhow.com/plant-problems/disease/get-the-cure-for-powdery-mildew.htm
http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/powdery-mildew/