Coffee is so steeped in modern culture that humans produce about 15 million tons of used coffee grounds each year. That’s why people have been trying to figure out what to do with those grounds for years.
Using Coffee Grounds in the Garden | Everything You Need to Know
One of the most common uses I keep reading about is that you can just throw your used coffee grounds in your garden. As with a lot of gardening advice, there is a lot of nuance to this: just throwing used coffee beans in your garden is not a good idea, but there may be a few niche uses where it does make sense.
Let’s start with what’s in coffee grounds. Coffee itself is a bean, and all beans are natural nitrogen fixers, meaning they produce available nitrogen for the soil. In addition to the protein in the bean, there are also oils, lipids, triglycerides, fatty acids, cellulose, and sugars. Additionally, the brewing process can add lignin (an organic polymer), phenols (an aromatic), and essential oils, all of which are not a problem in the garden and can even be antioxidants. There are three organic bodies that can break down and use all of those compounds in the garden: fungi, soil bacteria, and earthworms. So far so good, right?
To dispel the first myth surrounding coffee and your garden, adding it to the soil around blueberries, hydrangeas, and azaleas will not create an acidic environment, even though these plants love coffee.
