Will adding iron sulfate to my lawn help rid my lawn of mushrooms and toadstools?
While Iron sulfate and other broad-spectrum fungicides can be used, spaying directly onto the mushrooms usually does little good. Most of the fungus is below ground and inaccessible to the chemicals. Mixing 2 tablespoons of baking soda per gallon of water and spraying at the first sign of mushrooms can sometimes be helpful in reducing their growth. Here is an article that you may find helpful: https://www.gardeningknowhow.com/lawn-care/lgen/eliminate-mushrooms-in-your-lawn.htm