Originally Posted by rhubarb

Looks like this thread is a little older than I first suspected.... But here is my .02. Coffee is an excellent amendment to the garden. Used grounds are not as acidic as the liquid that is the coffee that you drink. The acid is in the coffee you are drinking and has therefore been leached out of the grounds through the brewing process to some degree. Use the grounds as a perimeter mulch around the entire vegetable garden. Slugs hate coffee grounds. It also turns out they hate caffeine. Recent research has shown that caffeine at approximately 200% of the strength of normal coffee actually kills slugs and snails.

Toads love coffee grounds and are also a major beneficial predator in the garden. Coffee grounds will not dramatically increase acidity if mulched on top and not worked into the soil in moderate amounts. Lay newspaper down in several layers around plants to deter weeds and mulch with coffee grounds on top.

If suffering from a slug/snail invasion spray vegetables with room temperature coffee liquid at dusk. This has been extremely effective in our garden.

And yes, absolutely, if you want worms put coffee grounds down. Coffee and mint plants are the two major worm attractors.