I have run across the same thing, too. It is some sort of fungus. I scraped it off with the hoe and let the ground dry out, it didn't grow back again. Weird stuff.

Thanks for the reply. I had a neighbor come by and she too was mystified. However, her ten year old son was completely fascinated. I think he's going to come back and collect some for a science project.

I did some more checking and it sounds like it is "dog vomit slime mold". Nice name, kind of sums it up.

Yes, a descriptive & appropriate name. Had it appear a few years ago then vanish by itself. Besides the black spores it left behind, it did no harm.

I thought you were joking about the name. Ewwwwww

Here is a link that might be useful: Ewwwwww

another good link

Here is a link that might be useful: dog vomit slime mold

Ewwww, slime mold!! We were almost eaten by it last year. It overtook whole perennials. I lost a mature verbascum to the stuff. We had dozens of serving plate sized slime molds from spring through the end of August and it go so I didn't want to go in the garden anymore.

But guess what? I switched to shredded leaf mulch in place of the hardwood bark mulch I used to get, and we've not had ONE slime mold this year! We've had a few very beautiful and interesting looking mushrooms come up through the mulch, but those I can live with!

Tina, I had the same thing last year with hardwood mulch. I actually thought my neighbor's teenagers were throwing up at my house before heading home. Mine did no damage, but it looked so disgusting! No more hardwood for me either.

Ugh! We just had this discusting slime mold pop up today..
Unfortunately, it is in the mulch right under our new swing set we purchased for our kids. I don't want them getting into it by touching or stepping, so what can I do to get rid of it?? It seems as though there is nothing that can be done. I sprayed clorox on it and it turned a different color but a few hours later on the edges the bright yellow started reforming!! Does anyone have any ideas????
Thanks!!

I've had this appear several times. Unless there is some funky allergy, it is completely harmless. It is feeding off the decaying hardwood. Try to fluff up the mulch to reduce the moisture & that "should" knock down the mold for this year. Odds are it will reappear tho if you keep feeding it. It is very ugly & slightly disgusting but thats all. Won't harm people or plants.

Am I the only one that thinks they are cool?

Yes, I think you're probably the only one. :)

Had it too several years ago, after we got a free load of mulch from a tree cutting company. The mulch was free, and delivered too, but won't be getting that stuff again.

Natural mulch decomposes, whether it is expensive bagged stuff or free trimmings from a tree service. That's what makes it good for the garden (in addition to its' moisture-retention and weed barrier properties.) Generally, the more quickly a mulch decomposes, the more benefit it is to the plants. The mold is just helping in the process.

Yep, had that when I used cocoa mulch around my roses. I agree with scooping up what you can and tossing that..then fluffing the mulch up a bit on top so that it can dry out.

It seemed to appear almost overnight. Big wad of ugliness..even started to go up the stucco of my house. NASTY looking stuff. Didn't have it on my redwood bark, though...

never gotta that stuff and i am glad i have hard wood mulch but all ig et is mushrooms which can be so pretty.....although my honey suckles did awful i was so dissapointed.

Okay, I think they are cool too. Weird looking, but cool. And, although I use bark mulch, I've never lost a plant to them. I enjoy seeing all of the strange fungi nature has to offer.

Karen

Slime molds are very cool. There are many different kinds with many interesting shapes in their fruiting bodies (although the kind it sounds like you had aren't the most interesting). Some are beautiful under the microscope, with lovely spore shapes too. Before they freeze into their fruiting bodies, their tissue streams over the ground. If you've ever seen thin, squiggly lines of perhaps bright yellow material on leaf or wood litter, you may have been looking at an earlier form of the same beast.

Bitterwort