Coffee Grounds and Flower Beds

Q. Is it a good idea to work coffee grounds into soil in flower beds? Does it help?

A. Yes, coffee grounds are good. They add some, but not all, nutrients needed by plants and improve soil structure for better water drainage and air movement to the roots. This, in turn, improves plant growth.

            Coffee grounds are better if composted first, but adding them “raw” is one step in helping improve the soil as well.

            Don’t rely on coffee grounds alone. For instance, don’t go to your local Starbucks and add 100 lbs. of coffee grounds to a 4 x 8 planter or raised bed and call soil preparation done.

            Adding only coffee grounds is like eating only corn and expecting to maintain a healthy diet. You need a variety of different foods to remain healthy. Your garden also needs a variety of healthy ingredients from different sources for plants to remain healthy.

            A variety of minerals are needed by plants. Provide this variety by decomposing a wide variety of things in your garden soil besides coffee grounds.

            A very good article was written by Sunset Magazine about the nutrients in coffee grounds. 

 https://www.sunset.com/garden/earth-friendly/starbucks-coffee-compost-test

Probably the take-home lesson from this article about coffee grounds is about available nitrogen.

            There is plenty of nitrogen in raw coffee grounds but this nitrogen isn’t yet released or available for plants. Releasing this nitrogen to plants is done through composting or letting it sit in the soil and “rot” or decompose. That’s what composting is. It’s “controlled rotting”.

            Other things to add to flower beds in small quantities that round out available plant nutrients include wood ashes (not ash from coal or a petroleum sources), finely ground kitchen scraps (use a blender with a little bit of water to grind up kitchen scraps to a small size), shredded paper with black, not colored, ink, shredded cardboard, sawdust from wood but not particle board, leaves and grass clippings.

            When added to garden soil, all these “rot” over time and release minerals and nutrients. But make sure they are pulverized. The smaller the pieces, the faster they “rot”.

            Stop and think about it. Compost piles are mixtures of a wide variety of things but lumped together and managed so they “rot” faster. Finished compost makes a soil amendment with a wide variety of plant nutrients.

            The nutrient almost always in short supply by plants is nitrogen. Animal manure is added compost because of its high nitrogen content. Vegans use green plant parts which provides exactly the same kind of nitrogen.