Q.A white powdery substance has developed on the tips of our rosemary plant. moving down the branch. I trimmed off but it came back.
this plant was transitioned from our (Wisconsin) garden this fall into the house so we can use in cooking over the winter.
Certified GKH Gardening Expert
Yes, this will be powdery mildew. There are many ways to get rid of this. It is one of the easier diseases to conquer. This article will help: https://www.gardeningknowhow.com/plant-problems/disease/get-the-cure-for-powdery-mildew.htm