Does your lawn have either of these things?
Whenever we have a period of rainfall, warm temperatures, and high humidity, we always receive calls about mushrooms. We also receive calls about bluish-gray fungus on the lawn. The good news is that both of these are called saprophytic fungi, meaning they are not feeding on the grass itself. Therefore, neither lawn fungus needs to be treated with a lawn fungicide. Mushrooms are the fruiting body of fungi that feed on rotting wood underground and they may be a symptom of a lawn disease called ‘Fairy Ring’; but it does NOT need to be treated. You can just kick the mushrooms over and they will dry out within a day or so. And with slime mold, you can either wash the particles (technically called pustules) off or kick it off of the grass blades it attaches itself to. Generally, when the lawns dry out and the humidity diminishes, the mushrooms and slime mold will disappear.
Here is the link to our website that describes mushrooms
Finally, here is a link from Ohio State University that describes slime mold in more detail
Mark Schlossberg is the President of ProLawnPlus in Baltimore, MD. He graduated from the University of Maryland in 1977 with a B.S. in agronomy. He is the President of the Maryland Association of Green Industries, and past president of the Maryland Turfgrass Council.