Dog vomit fungus (Fuligo septica) is a type of slime mold most often found 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 fungus"—because the fruiting body (the part you see) is light-yellowish in color and looks a bit like scrambled egg curds. Dog vomit fungus and other slime molds are saprophytic, which means that they feed on decaying organic materials. They are not diseases and won't really 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, and there are steps you can take to decrease it.
- 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:
- Soil Type: Mulch
- Soil pH: 4.5 to 6.0
- Bloom Time: Non-flowering
- Flower Color: None
- Hardiness Zones: Worldwide
- Native Area: Worldwide
Growth of Dog Vomit Fungus
Slime molds like dog vomit fungus produce spores that are wind-borne. They are highly resistant 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. It is shortly after this stage that gardeners see the telltale, disgusting-looking fungus appear.
It often grows in wood mulches or along the sides of untreated wood, and sometimes in lawn grass. Occasionally, they'll grow on plants that are growing in mulch, and if a large enough colony forms, they may smother the plant. This is uncommon, however, and you'll usually just find the mold in the mulch itself.
You will most often see this slime mold in shady areas. It may move to a sunnier area to produce spores, after which the fruiting body turns black and shrivels away.
You will see this slime mold most often on mulch and other deteriorating plant material as it feeds on those. If your lawn has a lot of thatch, this could be the reason for seeing this slime mold.
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.
Slime molds live happily on compost piles.
Controlling Dog Vomit Fungus
The best way to get rid of dog vomit fungus is to break it up and dry it out. Fungus that is growing in mulch or leaf litter can simply be raked out and disposed of. It is best not to dispose of it in your compost pile unless you practice hot composting or you want more of the fungus to show up in your garden later.
Dog vomit fungus growing along lumber or tree stumps can be scraped away with a trowel or small shovel and disposed of. If you have it growing in your lawn or in plants, gently rake it out as best you can. A strong jet of water will help to dislodge any of the remaining fungi still clinging to the plants (although it may pop up again later.)
If dog vomit fungus continues to be a problem, consider switching from wood-based mulches to inorganic mulch, like gravel. But in most gardens, it doesn't pop up 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.
Toxicity of Dog Vomit Fungus
Considered relatively harmless, it is possible for susceptible people to have an allergy to this organism and it could trigger an episode of asthma or allergic rhinitis. If you are sensitive, wear a mask when handling the slime mold.
There is little concern if the dog vomit slime mold gets eaten by pets. It is generally not considered to be edible, but there are historical references to it being eaten by some human populations, and no reports of ill effects.
It won't introduce any toxins if you find it growing around edible plants in your garden. When the soil or mulch dries out, the slime mold should be gone and your plants will be safe to eat when you harvest them.