Have you noticed any slimy mold in your mulch this summer? We have had a bumper crop of Fuligo Septica, the “Dog-vomit” slime mold in the mulches this summer. Despite the unpleasant name, it is completely harmless to humans, animals and plants.
According to the North Carolina Cooperative Extension, slime molds consists of amoeboid cells or inconspicuous plasmodia that will slowly invade mulch areas or leaf litter. It eats bacteria, spores and organic matter, eventually moving to the top layer of mulch, leaf litter, or pinestraw. Sometimes it can even be found on a low growing plant or the foundation of a building. Once it has settled in a more exposed area, it will stop moving and become a fruiting (spore-producing) body. The bright yellow, frothy mass of Fuligo septica is first noticed at this point. The size can be just a few inches to up to a foot in diameter. The color will change to a dull orange quickly, then to a light tan as it dries out. In just a few days, it will break apart and the spores ,which are dark-colored, will be released and blow away to start new life cycles. After a week, all that will be left will be bits of a grayish/yellowish crust and a dusting of leftover spores. There isn't any point in trying to control Fuligo septica. It will not harm your plants, but if the sight is intolerable to you, you can remove it by hand or rinse it off with a hose. Most likely it will reappear this year, but probably not next year unless you apply new mulch. Planting to Grow, Jeff