I have Peony with powdery mildew - I plan to follow the homemade remedy spraying with the blend of baking soda, dishwashing liquid and horticultural oil. My question is: will using food based pure canola oil be an effective substitute for horticultural oil? Thank you, Denise
Certified GKH Gardening Expert
The recipe for the homemade solution is below. You can use canola oil instead of horticultural oil both are equally as effective.
Homemade remedy: Mix together a tablespoon each of baking soda, horticultural oil (or canola), and liquid dish soap (without bleach) with a gallon of water.
For more information on peonies and powdery mildew, please visit the following link: