In the United States alone, we use close to ten trillion coffee beans each year. After extracting the caffeine and the flavor, we leave most of that organic matter behind. At Casa Hayes-Boh, we generate a few thousand of those beans ourselves, and we apply them as much as possible in our gardens, where the hydrangea in particular are very happy with this diet.
Daily Shot of Coffee blog recently suggested this and three other uses for the grounds, some of which we will be trying. Coffee starts as a fruit, the skin, pulp, and two seed coverings of which are lost during processing. Ecological coffee production involves using each of those components for uses as varied as soil amendment (nutrients from some layers; structure from others) and cooking fuel.