Hi,
I am pretty sure what you have is something called "dog vomit fungus". Try to google it and you will find loads of info and pix. It is supposedly a harmless mold. I had it for the first time a few weeks ago, in several spots over several nights, and it has not harmed the plants it was covering. It grows in wood mulch. Since it is rather disgusting to look at, I clean it up, but it will go away on it's own.

Elisabeth.

We get it on our mulch every year during wet times -- or when we have to water, like from the drought. I am lazy, so I don't clean it up, and it just runs its course and disappears till next time, I guess. We have some spots now. Love that name, LOL. Dog Vomit.

Thanks to you both. It's progressed to having a brownish crush on top, and the earth is getting drier. I love that name too and it is a perfect name for the fungus. Pictures on websites that I checked have it exactly like it looks in my garden. To me, it's still weird, though, because I would not have expected something like this in a city yard. I learn something new about gardening every day!

I just saw this at a park here in St. Charles on the mulch - it does look like something a dog hurled... gross...

i will guarantee you it is dog vomit fungus! very, very common in mulched areas. it has nothing to do with defective muclh, is NOT a health hazard, and should not be removed unless you get it immediately. never attempt to move it omce it starts to crust, as it will look like a atom bomd went off, releasing zillions of spores!!
don't worry, that spot will be gone soon, with new spots possibly surfacing!

Through my quest to find out about this stuff, I was also told it's called slime mold. The spots have gone fairly quickly - few days - and, yes, new spots do occur. In my very limited experience, the new spots have shown up right after heavy watering or rain. This stuff if flat out ugly!