Using baking soda or potassium bicarbonate dissolved in water is a good treatment for various molds and mildews on garden plants.....An elderly woman I know had black mold invade her basement. Her son wanted her to move, get a contractor in, etc. The contractor wanted $20,000 for removal, replacement, painting and venting. The poor dear was beside herself cause she couldn’t afford it and I volunteered to help her. I used baking soda and about 12 scrub brushes for three days. Told her to hire a painter and I made him use a zinc based marine paint. The price? About $40.00 (plus the painter) and a case of beer or two for my labor.
Use baking soda and instant tea crystals mixed with water in a pump sprayer to treat lawn fungus.