It looks to me like dog barf or vomit fungus which is really a slime mold and is relatively common when mulch stays wet.

I linked below to some pictures of it via Google IMAGES and you can see that it comes in lots of different colors and shapes.

And here's an article with more detail:

http://botit.botany.wisc.edu/toms_fungi/june99.html

Hope that helps.

Carolyn

Here is a link that might be useful: Dog Barf Fungus

They look nothing like slime mold (dog vomit 'fungus') to me.

What I believe these to be are the 'eggs' (bad word, but that's what they are often called) of one of the stinkhorn fungi. I'll attach a good link with some pictures of these premature stages, as well as the mature fruiting body.

Please believe me when I tell you that the universally accepted common name is the Dog Stinkhorn. Scientific name is Mutinus caninus. I call it the dog thingie mushroom.

Very common in mulch. Look up 'dog stinkhorn' and dog stinkhorn eggs' for more pictures.

Here is a link that might be useful: Seein' is believin'

I had yellow dog vomit fungus this year but it didn't look like that. It really looked like a huge dog had barfed a big pile of yellow barf in my garden. I had two big patches of it that lasted a say or two. Didn't seem to hurt anything.

I meant to add, lois, that your stinkhorn is a true mushroom (unlike the vomit slime mold which is neither a fungus nor a mold) and earns its living by decomposing/recycling your mulch. It's a saprophytic fungi, and considered beneficial. But they are called stinkhorns for a reason.

Has no relationship to how much you water other than that the soil's moisture content is correct, the soil temperature is correct, and it's time for the fungus to do its thing.

The genus and species of what I referred to was in the middle of the text so you had to copy and paste it to read it.

And it does come in all colors and shapes as the Google IMAGES links shows and as others have also indicated with pictures at other sites where I read and sometimes post.

Never heard it called stinkhorn before, though, and I thought Lois said it was slimy inside.

Mutatis caninis? That's not the genus and species that was reffered to in that article.

Ah well, more to lean I guess. but I'll check out your stinkhorn when the Irene passes over if I still have power.

Carolyn, retired Microbiologist who used to talk about the slime "molds", just a general term that covers a lot and yes, I know they aren't fungi perfecta or imperfecta and the word "mold" is really just a general term that most folks can ID with. ( smile)

Thanks, everyone. While I'm glad to hear it's not going to hurt the tomato plants and apparently not an indication of bad gardening practice, I never expected to become a candidate for winning the Indecent Garden Award.

Um, when I clicked back on the link I attached Mutinus caninus appeared, and is labeled as such.

The round 'eggs' Lois referred to are extremely slimy if opened. Many of the stinkhorn species arise from these 'eggs'. Her's may not even end up being the dog stinkhorn but I believe that they will....they begin as those roundish white sacs. Maybe Lois will post an image as they begin to emerge from under the soil.

Remember, she found these under the mulch. That's where these white eggs live. The fruiting body will emerge from the mulch and everyone will become thoroughly grossed out.

Lois, if you begin to see vultures circling around your yard, you'll know that the stinkhorns have emerged. You can run out and take some pictures before the neighborhood children come out and stare at them. ;-)

Ok, I guess my whole yard just got lucky this year, haha. Here is a picture of what the 'eggs' seem to be producing; these growths are appearing in several gardens, not just the tomato garden. I haven't seen any vultures yet, though...

Lovely. Now you know why I call this particular stinkhorn the "dog thingie" mushroom.

Did you happen to put out a bunch of new mulch this year? Anyway...enjoy! You'll only have to wear a clothes pin on your nose for a few weeks.