Here is the recipe for the Powdery Mildew spray that I use. This is just one of many I found online from various sources,
To make 1 Gallon of spray:
You will need a 2 cup measuring cup and a pump sprayer that holds at least 1 Gallon of water to apply it.
Mix the following ingredients in the order listed, making sure #5 is added LAST.
1.) Fill measuring cup with 8 oz. of water
2.) Add 1 1/2 tbs. baking soda
3.) 1 tbs. Canola oil
4.) 1 tbs. insecticidal soap
5.) 1 tbs. WHITE vinegar
6.) Stir all these ingredients well
7.) Pour this mixture into your sprayer
8.) Add enough water to your sprayer to make 1 gallon of spray.
Spray your plants thoroughly to cover all infected areas. Do it when the air is calm so it doesn't drift or evaporate too soon.
This works very well on roses, too.
Repeat in 5 to 6 days if needed.
