HelpfulGardener.com

Hi
I had gotten some coffee grounds from starbucks...two bags worth about a month ago. Used the first bag, totally forgot about the second. Found that today, and there is mold on the grounds. I was going to use them for an area of soil that I am working on for next year (mulching, coffee grounds, shredded paper, leaves and black plastic is all I can come up with right now)

Anyway, can I still use them if there is mold on them? I don't have a compost pile, otherwise I'd just throw them in there
Thanks

I think it would be fine to use them. Molding is one of the first steps of the decomposition process, which is what composting is all about. It shouldn't hurt a thing.

Ok. I had thought about the mold being the beginning of decomp, but I didn't want to mess up my space for next year!

As a -- very generalized -- rule, white and green molds are ok but a black mold is viewed with suspicion. There is some confusion about red mold. There is at least one that is used for culinary purposes in Asia.

what's the black plastic for?

Usually the plastic is laid down over an area you want to solarize, ie cook out all the weeds, etc. But it tends to kill all the life in your soil too. You don't want to do that if you are putting down the coffee grounds and other stuff you mentioned.

Hmm...ok

so, cover it with a few layers of newspaper instead?

yup... if the idea is you are trying to kill weeds or grass to turn it into a veggie bed next year. But more than a few. Chop down the weeds, water well, lay down a bunch of layers of newspaper, water well again and then put all the other stuff down on top. If it isn't all grass and weeds, just dirt you are working on enriching, you can skip the newspaper too.

worms LOVE rotten coffee grounds, absolutely LOVE them.

Soil
I put a lot of them into my worm bin. However, I'm not too sure an 5 lb bag of used grounds would be a very good idea...especially considering I just dehydrated watermelon, cantaloupe, and oranges...and they got all the peals and rinds!

Question though...how to you tell they are actually eating the grounds? Could they just be getting sifted to the bottom? I've actually wondered about this...

worms don't eat the grounds, or the rinds you gave them. They merely shred these things to create more surface area to support the microbes they eat.

So to answer your question, your bin is really a compost bin with worms working in it. The microbes are eating the food. So it's not really possible for coffee grounds to remain intact for very long in the bin. Even if they managed to escape the worm gullet, the microbes still eat them.

Ahhh...that makes sense....