extension.oregonstate.edu/gardening/...-composting
Coffee grounds are a great addition to the garden and compost pile. Help to recycle this great organic resource and reduce the amount of organics going to the landfill!
Some information about coffee grounds:
- Coffee grounds are about 2% nitrogen by volume.
- Grounds are not acidic; the acid in coffee is water-soluble so the acid is mostly in the coffee.
- Coffee grounds are close to pH neutral (between 6.5 - 6.8 pH).
- Coffee grounds improve soil tilth or structure.
- Coffee grounds are an excellent nitrogen source for composting. They have a C/N ratio of 20/1. In informal trials with OSU/Lane County Extension Service, Compost Specialists sustained temperatures of 140 O-160 OF have been recorded for up to two weeks (when coffee grounds were 25% of the material in the compost pile by volume).
- Anecdotal evidence suggests coffee grounds repel slugs and snails in the garden.