How to Care for Peace Lilies

9. Possible diseases and pests

There are a few possible health issues that a peace lily can have, usually easily solved. Yellowing leaves can be caused by overwatering or underwatering, or sometimes that leaf is just getting old and ready to fall out. Brown leaf edges are usually from too much sunlight or over-fertilizing, but they can also be caused by not enough water or humidity. If you start getting fungus gnats, water your plant a bit less and let the topsoil dry out a bit more. If that doesn’t work, you may need an insecticide or transplant. Other pests such as scale and mealybugs need a thorough leaf washing. Wipe down the leaves with soapy water until signs of these bugs are gone. Experiment with watering, fertilizing, and sunlight to see what your peace lily thrives on.