Dog Vomit Slime Mold Profile

Yellow dog vomit slime mold on decayed bark

The Spruce / Evgeniya Vlasova

Dog vomit slime mold (Fuligo septica) might appear to be a fungus, but it's actually not--it's a type of slime mold in the Kingdom Protista, not Fungi. It's actually more closely related to an amoeba than a fungus! True fungi have a cell wall and digest their food with exoenzymes before ingesting it--but dog vomit slime mold ingests its food, then digests it. You'll most often find dog vomit slime mold in moist, shady areas and on materials such as mulch, rotting logs, leaf litter, and untreated lumber. It is also known by another nickname—scrambled egg slime mold—because the fruiting body (the part you see) is light-yellowish in color and looks a bit like scrambled egg curds. Dog vomit and other slime molds are saprophytic, which means that they feed on decaying organic materials. They are not diseases and won't harm your plants. It is most likely to show up during warm, wet periods, sometimes seeming to pop up out of nowhere overnight. The good news is that it is harmless, but it's challenging to prevent it, as the spores spread easily and can survive for years.

Botanical Name Fulgio septica
Common Name Dog vomit fungus, dog vomit slime mold, scrambled egg slime, flowers of tan
Plant Type Slime mold
Mature Size Up to 8 inches in diameter and 1 inch thick
Sun Exposure n/a
Soil Type Moist
Soil pH 4.5 to 6.0
Bloom Time Non-flowering
Flower Color n/a
Hardiness Zones All zones
Native Area Worldwide
Yellow dog vomit slime mold closeup

The Spruce / Evgeniya Vlasova

Yellow dog vomit slime mold on decayed wood near foliage

The Spruce / Evgeniya Vlasova

Growth of Dog Vomit Slime Mold

Slime molds like dog vomit produce spores that are wind-borne. They are highly resilient and can survive even during hot, dry weather. The spores can remain viable for several years, waiting for conditions to be favorable for growth. When warm, moist conditions are present, the dormant spores absorb moisture and crack open to release a swarm sphere. Shortly after, the telltale, disgusting-looking slime mold appears.

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 may smother the plant. This is uncommon, however, and you'll usually just find the mold in the mulch itself.

Light

You will most often see this slime mold in shady areas, but it also appears in sunny spaces, too. After its growth phase, the fruiting body turns black, produces spores, and shrivels away.

Soil

You will see this slime mold most often on mulch and other deteriorating plant material it feeds on. If your lawn has a lot of thatch, this could be the reason for seeing this slime mold.

Water

Slime molds are most often seen in wet conditions and moist substrates. The spores can survive for long periods and then germinate after a heavy rain. When the slime mold dries out due to lack of moisture, the fruiting body will deteriorate. Often the slime mold itself will move to a drier area to produce spores. If you want to get rid of it, don't water it.

Temperature and Humidity

While moist, wet, humid conditions might be ideal, these slime molds can be seen in every climate.

Fertilizer

Slime molds live happily on compost piles.

Controlling Dog Vomit Slime Mold

While you can try to remove dog vomit slime mold with a shovel, it's nearly impossible to eradicate it. The prolific spores spread easily and will remain in the organic material in the garden. However, if you dislike the aesthetic of dog vomit slime mold in your flower beds or near the front walkway, simply use a shovel to scoop 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 may show up in your garden later.

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 mold. 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 fungi, 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, like 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 may opt to let it be and simply hope for drier conditions in the future so you won't have to see it again anytime soon.