Some helpful information to combat powdery mildew from our GardenOntario Facebook Group:
Powdery Mildew. This is now happening in many gardens because of all the recent rain and humidity. Here is a safe way to help restore your plants. Combine one tablespoon baking soda and one-half teaspoon of liquid, non-detergent soap with one gallon of water, and spray the mixture liberally on the plants. Mouthwash. The mouthwash you may use on a daily basis for killing the germs in your mouth can also be effective at killing powdery mildew spores.
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