I usually take home about 4 pounds of grounds from the coffee stations
here at work every day. Coffee grounds are considered a "green" for
composting where you want a combination of green and brown ingrediants.
I forget the ratio, though. But composting is not a precise activity.

I've also heard that grounds are 2% nitrogen.

I put them in my main bin where the kitchen scraps go and in the worm
bin with newspapers. Actually I add them to all of my heaps. I have
pretty good compost. It's a little weedy and needs to be screened
because I put sticks and twigs in it. But I consider coffee grounds to
be a vital ingredient. I don't have that much in the way of other green
ingredients and I have lots of dried leaves, dried grass and pine needles.

I don't add citrus to my worm bin, but I do to the main bin. Which has
quite a lot of worms. I guess they can avoid the citrus on their own.
The worms seem to like the coffee grounds. And compost the paper
filters, too. You don't have to separate them out.

simy1 wrote:

Anthony Ward wrote:

The canteen at my workplace is trying to improve its recycling
statistics and so is bagging up the used coffee grounds from the
machine and offering this to customers for their garden compost bins.
A colleague has said this is not a good idea because the grounds are
too acidic. I would appreciate knowing the thoughts of experienced
gardeners on this please. I am not particularly wanting to grow
acid-loving plants.
I have also heard that one should not add citrus peel to the compost
bin for the same reason. Does the group agree?


no. finished compost is near neutral under all circumstances. if you
can get buckets of coffee (or buckets of peels) go for it.