Disgusting to look at but fortunately not harmful to the plants. In fact its appearance gave it the common name of dog vomit fungus. This slime mold feeds on organic matter and is often found on woodchips, cocoa bean shells and other organic mulches during wet periods. Rake the mulch surface occasionally during wet weather to loosen and dry the mulch and reduce problems with the mold. If the problem occurs on cocoa bean shells try mixing it with rice hulls. They help separate the shells, increase air circulation and reduce slime mold. Rake slime molds as they appear. This speeds the drying process and improves the appearance of your garden. Otherwise let them dry and disappear on their own.