Are Coffee Grounds Good for Plants?

Are coffee grounds good for plants?

Everyone wants to know: are coffee grounds good for plants? It’s one of those gardening tips that gets repeated so often it feels like it must be true. Save your morning coffee grounds, sprinkle them around your plants, and you’ve got free fertilizer.

The truth is a little more complicated.

Used coffee grounds contain some nitrogen and small amounts of other nutrients, but they aren’t a complete fertilizer. And despite their reputation, used coffee grounds generally aren’t highly acidic. Brewing removes much of the acidity, so adding grounds isn’t a reliable way to lower your soil’s pH.

Can Coffee Grounds Hurt Plants?

A small amount probably isn’t a problem. Regularly dumping coffee grounds directly around plants, however, isn’t something we recommend.

Coffee grounds are made of very fine particles. In thick layers, they can compact together and interfere with water and air movement through the soil. Coffee also contains biologically active compounds, including caffeine, and concentrated amounts may inhibit the germination or growth of some plants.

Natural doesn’t always mean beneficial in unlimited quantities.

Compost Them Instead.

So, are coffee grounds good for plants? They can be, after they’ve been composted.

Add used grounds to a diverse compost pile along with leaves, garden debris, food scraps, and woody material. Fungi, bacteria, insects, and other decomposers will break everything down and turn it into something far more useful to your garden: finished compost.

Healthy gardens don’t depend on one magical ingredient. They depend on healthy ecological systems.

Plant diverse native species. Keep living roots in the soil. Leave fallen leaves where appropriate. Reduce unnecessary disturbance. Allow organic matter to decompose and protect the organisms responsible for cycling nutrients.

Your morning coffee can be part of that cycle. Just put the grounds in the compost pile first.