Q.Powdery Mildew
To combat this mildew, it is said to use a hydrogen peroxide mix. What is the mix? I used about 20 oz to 1 gal of water. Am I close?

Certified GKH Gardening Expert
Pour a quart of standard 3 percent-strength hydrogen peroxide into a gallon-sized spray bottle. Add three quarts of water and shake the spray bottle to mix its contents thoroughly. If you're using a bigger or smaller bottle, adjust the measurements so you're mixing (1:3) one part hydrogen peroxide and three parts water.