Dog vomit and other slime molds are saprophytic, which means they feed on decaying organic matter. You’ll most often find them in moist, shady areas and on materials such as mulch, rotting logs, leaf litter, and untreated lumber. They’re most likely to show up during warm, wet periods—sometimes seeming to pop up overnight. They are not diseases and won’t harm your plants. Still, they are not something most people go out of their way to plant because they’re not visually appealing. Plus, the spores can spread quickly and easily, and they can survive for years. Fulgio septica often grows in wood mulches, along the sides of untreated wood, on compost, and sometimes in lawn grass, particularly if there’s quite a bit of thatch in the lawn. Occasionally, it grows on plants that are growing in mulch. And if a large enough colony forms, it might smother the plant. This is uncommon, however, and you’ll usually just find the mold in the mulch itself. After its growth phase, the fruiting body turns black, produces spores, and shrivels away.
Light
You will most often see this slime mold in shady areas. But it can appear in sunny spaces, too.
Soil
Dog vomit slime mold appears most often on mulch. But it essentially just needs some kind of decaying organic matter (which it feeds on) to show up.
Water
Slime molds like wet conditions and moist substrates. The spores often germinate after a heavy rain. And when the slime mold dries out due to a lack of moisture, the fruiting body will deteriorate. So if you want to get rid of it, don’t water it and attempt to dry out the area where it is.
Temperature and Humidity
Slime molds prefer warm temperatures between roughly 60 and 80 degrees Fahrenheit, as well as wet, humid conditions. But they can survive in many types of climates.
Fertilizer
Slime molds don’t need fertilizer for growth, though they can live happily on a compost pile. They simply must have decaying organic matter on which they can feed.
Controlling Dog Vomit Slime Mold
While you can try to remove dog vomit slime mold, it’s nearly impossible to eradicate it. The prolific spores will spread easily and remain in the organic material of the garden. Still, there are some steps you can take to minimize its impact. For dog vomit slime mold in mulched flower beds, simply use a shovel to scoop out the top layer of the mulch that’s feeding the slime mold, and dispose of it in an inconspicuous area. It is best not to dispose of it in your compost pile unless you practice hot composting. Otherwise, more of the fungus might show up in your garden later via the compost. Dog vomit slime mold growing along lumber or tree stumps can be scraped away with a trowel or small shovel and disposed of. But remember, you’ll also be releasing spores as you scrape the slime mold. So it might come back in a nearby location. If you have it growing in your lawn or in plants, gently rake it out as best you can. Do not use a strong jet of water to dislodge any of the remaining slime mold, as it will simply scatter the spores. If dog vomit slime mold continues to be a problem, consider switching from wood-based mulches to inorganic mulch, such as gravel. But in most gardens, it doesn’t appear often enough to be a real issue. And because it typically doesn’t harm plants, you can opt to let it be and simply hope for drier conditions in the future that won’t support its growth.
