Dog Vomit Slime Mold

Have you ever walked out into the garden and seen what looks like Fido urped up his dinner? This fascinating pile of yuck is a slime mold.

​Dog vomit slime mold (Fuligo septic), also known as Scrambled Egg slime mold, often grows on bark, wood chip mulch, or other rotting plant material. It starts looking bright yellow and then turns an unappetizing brownish-gray in a day or two. If you try to hose away this mess, the water will roll right off, or a cloud of spores will rise, spreading the slime mold throughout the garden.

Slime molds are like the “blob” from old horror movies. These bubbly-looking slimes travel across an area, devouring bacteria, yeasts, fungi, and other organic matter. Not to worry, though, because you can easily escape. They only travel about 1 mm an hour. As they move, slime molds develop fruiting bodies that produce spores that can make new blobs.

Day one (top) and 2 days later (bottom). Note the change of position relative to the seashell.

Unlike other plant cells, slime mold cells have no cell wall. Instead, they are one giant, gooey cell with countless nuclei. This enlarged cell is called a plasmodium. As the tissue breaks down, you may see dark-colored spots of red liquid on the surface. In a couple of weeks, the mass will flatten out and dry.

Besides being funny-looking, dog vomit fungus is not harmful. Even if there was a way to get rid of them (which there isn’t), they don’t hurt anything other than your sense of beauty and aesthetics. Slime molds are important to garden biodiversity. They help break down woody materials and return those nutrients to the soil.

Did you know that slime molds can be used to determine the most efficient layout for streets and highways? It’s true!