Boston Ferns remove more formaldehyde than any other plant. They’re also highly efficient at removing other indoor air pollutants, such as benzene and xylene—components of gasoline exhaust that can migrate indoors if you have an attached garage. The downside to these plants is that they can be finicky. You need to feed them weekly in seasons when they’re growing, monthly during the winter, and they like to be watered regularly. Depending on the humidity and moisture levels in your home, you may need to water them or mist their leaves daily.