Fungus in Mulch

Photo: Randy Lemmon

I've heard it described many ways …

"An ooze coming from my mulch."

"Something that looks like wet scrambled eggs."

"I think my cat regurgitated his breakfast in my garden."

"I swear it's as if a dog has thrown up in my mulch."

And it is officially defined as …

Scrambled egg slime mold

Saprophytic fungus

Or, just plain slime mold.

If you deal with shredded hardwood mulch in a landscape, sooner or later you're going to have an incidence of slime mold. It normally starts as a wet-yellow or wet-orange blob on the top of a mulched bed. Then, in most cases, it hardens and turns tan and finally becomes a brownish pile of dust.

While the wet stage only lasts 24-36 hours, the hardened, brown-spore stage can last up to a month.

In 1973, yellow, pulsating blobs of "scrambled egg" slime plasmodia appeared in Dallas and caused a near panic. Some residents there thought these "blobs" were either aliens from outer space or mutant bacteria preparing to take over the earth! Typical Dallasites!

Although it may seem odd to some, "scrambled egg" slime mold and a similar type are fried and eaten by natives of Veracruz, Mexico. They're called "caca de luna" by the locals. I'm not making this up!!!

In the Houston area, it is almost always associated with shredded hardwood mulches. It gets energy from organic matter below the soil line rather than from the sun, like green plants. If a fungus feeds on living organic matter, it is called parasitic. If it feeds on nonliving organic matter, it is called saprophytic (pronounced: sah-pro-fit'-ik).

Is it a good thing or a bad thing?

I think it's a good thing, because it shows high levels of organic matter trying to do something. Can you control it, or do you even need to?

You can control it simply by flipping it over before it gets to the hardened stage. Anyone who has tried to flip the hardened stage with its countless brown spores knows what an effort in futility that can be. But if you catch it in that oozy, wet stage, you can flip it over and soak the area with a fungicide like Consan. Once it's dried and hard, forget about spraying it with anything.

Another saprophytic fungus with which we are all very familiar in our lawns is slime mold.

Photo: Randy Lemmon

It shows up as a little area of grass that looks as if someone coated the blades with oil and then sprinkled cigarette ashes or salt and pepper on the blades. Again, Consan brushed on the blades in that particular area will help to suppress the mold. But, again, you don't have to do anything if you don't want, because it will go away on its own.


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