We’ll Tell You: It isn’t really a mold or fungus, nor is it a plant or animal. Slime mold Fuligo septica, also known as “Dog Vomit Fungus”, is a primitive, single celled organism, with spore production.
Did You Know? In a class all to themselves, with over 700 different varieties, slime molds are quite common in our area and are typically found in damp, shady spots with abundant organic matter, like mulch or thick grass clippings. Slime mold does not feed on living plants. As a matter of fact, they are saprobic organisms, meaning they derive their nourishment from nonliving or decaying organic matter. Although unsightly, the organism may actually be helping your plants, by consuming pathogens and bacteria that could harm them. Slime mold poses no real threat to animals or humans.
Bottom Line: Most people would find something resembling vomit in their lawn or garden unattractive. However, slime mold is an important part of the soil ecosystem and indicate that there is moisture and organic matter in the soil. This is a good thing, because lawns and landscapes usually thrive with ample moisture and organic matter.