It looks like dog vomit and travels in an oozing blob, but slime mold isn't dangerous

·2 min read

Jul. 22—It looks a bit like something out of a science fiction movie: an oozing, creeping substance that can spread several feet in just 24 hours. But though it's especially prevalent in Maine this summer, they aren't harmful.

Slime mold is a grouping of single-cell amoeba that meld together to behave as a larger organism. The amoeba live in soil and can produce millions of spores below the surface that, when disturbed, can escape, come together and creep around eating decayed organic material.

According to Dr. Alicyn Smart, director of the University of Maine Cooperative Extension's plant disease diagnostic laboratory, slime molds do best under wet conditions. Normally July and August tend to be dryer months in Maine, which is why the slime molds are more numerous in spring and fall.

"This is usually the time of year we don't see them," Smart said.

But this year has been different, with a cooler, wetter July.

"I've been receiving many reports of people seeing them with both farmers and gardeners saying they are finding them everywhere from tomatoes in hoop houses to the turf in lawns," Smart said.

Other than spores possibly causing mild irritations to people with respiratory issues, most slime molds are also harmless to humans, pets and wildlife.

Worldwide there are more than 900 species of slime mold, according to Smart. The most common one in Maine is the dog vomit slime mold, which is bright yellow or brownish red.

Though they aren't actually a fungi, like real mold, some slime molds in Maine resemble fans and, depending on the species, can range in size from several inches to a couple of feet in diameter.

"Slime molds are not bad things," Smart said. "They are just indicators we are currently in a really moist environment, which we are all pretty much aware of."

In Maine, slime molds are most commonly found on mulch, according to Smart. But they also like dead leaves, decaying wood, turf, seedlings and plants. They come in a variety of colors — except green due to the fact they have no chlorophyll.

If you spot slime mold on mulch, Smart says to remove that portion and throw it away.

"Otherwise, it's not going to harm your plants or fruit and it's perfectly okay to eat fruit or vegetables that have slime molds on them," Smart said

Slime molds easily rub off. You should always thoroughly clean any fruit or vegetables before consuming them, slime mold or not.

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