With the warm, humid weather, accompanied by occasional showers comes the predictable appearances of slime molds. If you have never seen them before, they can be somewhat disconcerting. Some are downright disgusting-looking, with disgusting-sounding common names such as the common “dog-vomit slime mold” It’s name tells you what it looks like (at least it doesn’t smell)!
What are slime molds? They are primitive life forms that for most of their existence feed on decaying organic matter. At some point in time, they go into a reproductive mold, and begin oozing up onto surfaces, crawling like amoeba, forming a mass of “stuff” which quickly dries and releases spores.
One of the more common slime molds we see is on lawns, usually greyish in appearance, kind of like cigarette ashes dumped out on the grass. Sometimes they are black and oily in appearance.
Dog vomit slime mold is usually
yellow and brown and shiny, later turning crusty and thick. I usually see it in flower beds where a lot of wood product (bark mulch or compost) has been used. It looks like Fido barfed in the garden.
The good news is that they are harmless to the lawn and garden, and will disappear once it gets hot and dry. You can ignore slime mold, study it, or hose or sweep it away. Kick it and you will likely get your shoes black with all the spores waiting to be dispersed.
For further edification, here are some University references on slime molds: