Box hedge

Question

My buxus hedge is covered in an ash like substance – almost like cigarette ash but doesn’t smell or feel like that.

Any suggestions?

Answer 1

This sounds like Downy or Powdery Mildew.

https://www.gardeningknowhow.com/plant-problems/disease/downy-mildew.htm

https://www.gardeningknowhow.com/plant-problems/disease/powdery-mildew-homemade-and-organic-remedies.htm