I have bee balm plants that have powdery mildew. 3 questions: is it caused by wet or dry conditions? Is a spray of water and milk really an effective preventative? Once it is on the plant, how can I get rid of it (i.e. commercial spray or other recommendation)?
Powdery Mildew and Bee Balm
Certified GKH Gardening Expert
Powdery mildew loves moist conditions, though even plants that are somewhat dry can be affected. A weekly spray of milk at a concentration of 1 part milk to 9 parts water may significantly reduce the severity of powdery mildew infections. Neem oil is also effective in treating powdery mildew. For more information, these articles will help: https://www.gardeningknowhow.com/plant-problems/disease/get-the-cure-for-powdery-mildew.htm