Mulch mold — It’s certainly not our favorite topic to cover in the garden, but it can be quite alarming to come home to the clump of slime on your fresh bark mulch! It may appear in a range of colors and textures throughout the year and the good news—it’s usually harmless.

Where did it come from?

Like many things in your garden, plasmodial slime molds spread via organism and wind! The mass has no brain, but can move about to find bacterial nutrients to feed on for the time being. It did not come from any plant disease, or the mulch it hovers on.

Why do I have it?

Slime molds thrive in wet conditions, and mulch is designed to hold moisture. You have organic matter mixed with moisture to thank! In rainy seasons or after a large amount of rainfall, you are the most likely to find the unpleasant guest, sometimes in several places, around your garden.

How can I get rid of it?  

The presence of slime mold is NOT a cause for concern. It usually does not damage any plants.  If you find it unsightly, you can simply scoop up and dispose of it. Rake the space to release some of the moisture in the mulch and the problem should take care of itself. As the weather dries up, so does slime mold- in a few days it will be gone.

There are a couple preventative measures you can take including regularly raking your mulch during periods of great humidity. We do not suggest treating your landscaping with any chemicals to combat the formation of natural mulch mold.