Coffee grounds provide nutrients to gardens when used properly as a mulch or compost ingredient. They should be mixed with browns like leaves to balance the pH. Coffee grounds have a high nitrogen content and can be applied directly, used in compost, or fed to worms to improve soil quality and speed decomposition. Gardeners should consult local experts on the best application based on soil conditions and plant needs.

1. Let Starbucks help your garden grow 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.
For more information about composting, here are a few helpful Web sites:
compostingcouncil.org
mastercomposter.com
What's in Coffee Grounds? Starbucks commissioned a study in 1995 to better
understand the make up of the organic matter we call coffee grounds. The following
is the result of an analysis of our used coffee grounds performed by the University
of Washington College of Forest Resources:
Primary Nutrients
Secondary Nutrients
Nitrogen 1.45%
Phosphorus ND ug/g
Potassium 1204 ug/g
Calcium 389 ug/g
Magnesium 448 ug/g
Sulfur high ug/g
Notes:
ND = indicates sample is below detection limit
ug/g = microgram / gram