Water: Keep the soil moist, but do not overwater. Peace lilies can tolerate short periods of dry soil, but their leaves will start to brown if neglected for too long. Peace lilies are sensitive to chemicals commonly found in tap water, such as fluoride, which may cause brown leaf tips. Use filtered, room-temperature water, if possible.
Temperature: Peace lilies enjoy high humidity. Misting their leaves or placing their pot atop a moistened tray of gravel can help to increase humidity.
Fertilize: Peace lilies are not heavy feeders, so fertilize only occasionally. To encourage spring and summer growth, fertilize every 6 weeks or so with a balanced houseplant fertilizer starting in late winter.
Temperature: Peace lilies are a tropical plant, so keep them in temperatures above 60°F (16°C) and away from cold, drafty windows. They do best in temperatures upwards of 70°F (21°C).
Light: Keep these plants out of direct afternoon sunlight, but in a well-lit area. An east-facing window is ideal, as they will be exposed to the warmth of the morning sun but avoid the intensity of mid-day rays.