You can use coffee grounds to fertilize your anthuriums if you dilute them in water and irrigate your indoor plant with the concoction. Be aware that this fertilizer is incredibly rich in nitrogen and will promote lush leaves, but not the appearance of blossoms. And if you have a species that bears those attractive pink, red, or blue flowers, you should incorporate a high-phosphorus fertilizer in your routine. Finally, coffee grounds can increase the acidity of the soil if you use them too frequently, so make sure to have a soil pH meter at hand. (If the pH level of the soil isn’t adequate for your anthuriums - between 5.0-6.0 - your plant won’t be able to absorb moisture and nutrients properly).