Q.Powdery Mildew on Roses
I have a limited budget. I would like a recipe to make spray that removes powdery mildew. I heard that you can use Murphy’s Oil Soap and baking soda. Not sure the ratio of the ingredients, so if you could help me, I would be grateful.
Certified GKH Gardening Expert
If this is still too costly, then here is a recipe you can try: 3 tablespoons baking soda plus 1 tablespoon of Murphy's oil soap or a lightweight horticultural oil in 1 gallon of warm water. Mix well and let cool. Mix or shake up well again just prior to spraying. Apply this spray every 7 to 10 days until the powdery mildew is gone. Be sure to spray under the leaves as well.