Plants love coffee as much as you do. Coffee grounds can be used as a productive fertilizer because it adds nitrogen, potassium and a dash of magnesium to the soil. The consistency of coffee grounds is also handy for soil health.
“When you put coffee in your percolator it’s very light. At the end, it’s very heavy and it retains water,” says Brad Walker, founder of ReGround Organics in Ontario, Canada. “If you take that principle around your house, basically what you can do is mix it with your soil and help it retain water.” The aeration attracts worms and keeps the soil from getting hard like clay. Coffee grounds are especially good for flowers like azaleas, hydrangeas, rhododendrons, camellias and roses that thrive in acidic soil.