Coffee As Plant Fertilizer

Coffee has more value than just taste.

The value of coffee goes far beyond that first cup of morning brew that so many people look forward to every morning. There are qualities in the grounds that make it not only an excellent fertilizer for the garden, but a great support for the good of the environment.

Fertilizer Values of Coffee Grounds

According to a study at the University of Nebraska, coffee grounds contain low levels of nitrogen as well as small amounts of calcium and magnesium, and traces of salt. Although fresh grains of coffee have high acidic levels, once they have been brewed the acidic levels become low, which makes them a good additive to alkaline soils. For large gardens, a ratio of 10 pounds of dry coffee grains would be applied to every 1000 square feet of soil. However, they suggest that coffee grounds not be used as mulch because the composition will clump and decrease aeration.

Coffee in the Compost

Coffee grounds are excellent components of a composter.

Coffee grounds are an excellent component for composting, not only because they are readily accessible in most households, but because of their composting value. According to Cindy Wise, coordinator of the Composting Specialist Program at OSU, coffee grounds maintain high temperatures, reduce potentially dangerous bacteria and kill seeds from weeds and vegetables in the pile. Both the grounds and the paper filters break down in the composter and when they mix with other household compost and garden trimmings, they work together to create rich, organic soil, while increasing the nitrogen balance in the soil.

Direct Fertilizer

Coffee grounds can be mixed in with the garden soil.

Coffee grounds are a great replacement for the nitrogen element of fertilizers, which is identified on fertilizer labels as the first of the three numbers. Since the grounds release nitrogen slowly into the soil, they are an excellent source of food for plants such as rhododendrons and azaleas. Simply sprinkle one or two cups of coffee grounds onto the soil around the base of each plant and gently dig them into the soil. Use this in place of nitrogen fertilizer for a natural and environmentally friendly fertilizer.

Coffee Grounds and Worms

Earth worms are attracted to coffee grounds.

Worms are crucial to a healthy garden as they provide constant irrigation for the roots and eat the tiny insects that can potentially harm the plants. The coffee grounds attract the worms and become a nesting area for them. When the grounds are spread evenly in the garden, worms will begin to populate and aid in the growth of your garden.

New Plant Beds

Mixing coffee grounds with soil before planting is an excellent way to nourish the soil. For large gardens, till the ground into the top 6 to 8 inches of soil and then plant your garden. Water very well once the plants are in because this will release the nitrogen values from the grounds and give the plants an excellent start.

References

• University of Nebraska Lincoln: Recycling Coffee Grounds
• Talk about Coffee: Coffee Grounds and Composting

Resources

• Oregon State University: Compost Specialist on Coffee Grounds