Garden Hacks: Composting with Coffee Grounds

My grandmother went out every morning with her coffee grounds to spread at the base of her rose bushes. Maybe that’s why she had such lovely, fragrant roses. That was decades ago, but I remembered.

I picked up coffee grounds from a neighborhood coffee shop for close to ten years. When business picked up I enlisted two composting neighbors and we collected almost all of their grounds. 

Three times a week one of us arrived with a clean five gallon bucket to exchange for a full bucket of black gold. Before this symbiotic relationship developed, the coffee grounds were hauled to the trash. When the coffee shop closed I began visiting a Starbucks about a mile from my home. The baristas are eager to unload their grounds, saving them a trip to the trash. I stop by at least once a week. They often ask about my garden.

Coffee grounds speed the decomposition in my compost bin and add needed moisture. The grounds are slightly acidic which is an advantage for Western gardeners. They also add nitrogen and generous amounts of phosphorus, potassium, magnesium and copper.

Sunset Magazine sent a batch of Starbucks used coffee grounds to a soil lab for analysis. The report confirmed the value of coffee grounds as a soil amendment, not only adding nutrients but organic matter to the soil. Read The Starbucks coffee compost test at sunset.com. You can also read a short article on composting with coffee grounds at Serious Eats. 

Nice that the coffee that starts our day with a kick can also do the same for our garden soil.