Question
Hi.....
I live in the Pacific Northwest, Port Townsend, Washington to be exact, and I am a novice gardener, which means I know next to nothing. But I'm trying to change that.

I have planted some herbs to use in cooking, and I seem to have a persistent problem with powdery mildew on my sage plants. I have planted them in an open area in full sun thinking that would sort of solve the problem, but it hasn't.

My question is, I have heard that making up a solution of baking soda and water and spraying it on the leaves will help. Do you know how to make the solution? What is the ratio of baking soda to water? Is it better to buy a commercial fungicide instead? Do you know what the best one would be?

Thanks a lot in advance.
Cheers....Annie

Answer
Baking Soda Spray: for anthracnose, early tomato blight, leaf blight and spots, powdery mildew, and as a general fungicide Sodium bicarbonate commonly known as baking soda has been found to posses fungicidal properties. It is recommended for plants that already have powdery mildew to hose down all the infected leaves prior to treatment. This helps to dislodge as many of the spores as possibly to help you get better results. Use as a prevention or as treatment at first signs of any of the diseases.
To make: Mix 1 tablespoon baking soda, 2 1/2 tablespoons vegetable oil with one gallon of water. Shake this up very thoroughly. To this mix add 1/2 teaspoon of pure castille soap and spray. Be sure to agitate your sprayer while you work to keep the ingredients from separating. Cover upper and lower leaf surfaces and spray some on the soil. Repeat every 5-7 days as needed.