Composting with Coffee Grounds

Many folks are interested to know if and how they can use coffee grounds in their compost. First of all coffee grounds are a very good addition to your composting efforts. They would be considered a "green" or nitrogen source. C/N ratio about 20:1.

Coffee grounds can provide a valuable source of nutrition for your garden if used properly. The proper amount to be used depends on the condition of the soil and, more specifically, what you are growing in your garden. Check with your local gardening expert to see what is best for your situation. Here are a few general tips.

Applying coffee grounds directly in the garden

Coffee grounds can be applied along with other materials as a side dressing for vegetables, roses, and other plants. Coffee grounds are high in nitrogen, but are also acidic. Adding brown material such as leaves and dried grass to the mulch will help keep a balanced soil pH.

Mixing coffee grounds in your compost

Coffee grounds act as a green material with a carbon-nitrogen (C-N) ratio of 20-1. They make an excellent addition to your compost. Combined with browns such as leaves and straw, coffee grounds generate heat and will speed up the composting process.

Using coffee grounds in a worm bin: Worms fed with coffee grounds combined with other materials will flourish.

The measured pH of used coffee grounds was 6.9, with a significant amount of buffer capacity - adding the coffee to either acidic or basic solutions drove both towards neutral pH. The exact pH of used grounds will depend on the pH and alkalinity of the water used in brewing, but with any potable water, used grounds will be close to neutral pH."

Anecdotal evidence suggests that worms are very attracted to them so you can feel free to use them in vermiposting (worm bin) situations if you desire.

For more information about composting, here are a few helpful Web sites:

compostingcouncil.org (US Composting Council)
compost.org (Composting Council of Canada)
mastercomposter.com