Used coffee grounds are rich in nitrogen and make an excellent plant fertilizer for the garden. The grounds can be mixed into soil around existing plants or added to a bucket of water to create a liquid fertilizer than can be poured directly onto the ground. Spent coffee grounds can also be combined with other household waste, such as crushed eggshells, to improve growth of blossoming plants such as roses.
Loosen the soil around the plant with a trowel, taking care not to disturb the root structure.
Pour used coffee grounds around the perimeter of the plant, working the coffee into the soil with the trowel.
Add about 1/2 pound of coffee grounds to a bucket filled with water and allow the grounds to liquefy. This process moves faster if you place the bucket outside on a warm day.
Pour the liquid fertilizer created from the dissolved coffee grounds directly onto the soil around garden plants.