Americans consume nearly 400 million cups of coffee a day and about 150 million cups of tea per day. That comes to a lot of leftover tea bags and coffee grounds, most of which gets thrown into the trash. While Americans in large cities get most of their tea and coffee from coffee shops, many rural Americans brew their own coffee and steep their own tea, or used instant iced tea bags. For those of us who garden, we can save those coffee grounds and used tea bags for the compost and garden both.
Both coffee grounds and used tea bags are high in nitrogen, magnesium, copper, and potassium. They are both acidic, usually around 5.5 pH, making them too acidic to just dump in the garden time and time again. If used sparingly, both can be beneficial in many ways.
Coffee grounds can be dried and spread over high pH soils and then tilled in to help reduce the pH. Many garden vegetables are tolerant of acidic soils, some even prefer them. Caffeinated grounds can be spread lightly around hostas and other slug-loved plants; the caffeine in the grounds is toxic to slugs and snails. The grounds are also loved by earthworms, and are a great addition to the compost pile.
Cold coffee, if there is any left over at the end of the day, can be diluted with water and used to water acid loving plants like azaleas, blueberries, roses, ferns, gooseberries, and raspberries. It can also be used sparingly on garden containers and houseplants; the high nitrogen content is good for plants, but may reduce the number of blooms produced. Do not use coffee if creamers or fake sugars have been added!
Tea bags, if biodegradable, can be buried next to plants to provide nitrogen and nutrients, or to lower soil pH. They can also be added directly to compost piles. Just like cold coffee, cold tea can be diluted with water and used to water houseplants and acid loving plants.
See future posts to find out what else to do about your compost piles and garden.