Tropical peace lilies are evergreen, low-maintenance houseplants. They flower for a long period in the spring, but the long, strap-like foliage provides eye-catching color year round. Overwatering can kill a peace lily, since the roots cannot access the oxygen and nutrients they need when the soil becomes too wet.
Soil and Drainage
Peace lilies need rich potting soil that drains well. The plants don't tolerate wet roots or soggy soil. Using pots with drainage holes and drip trays ensures any excess moisture drains out of the soil and away from the plant's roots. After watering, empty the collected moisture from the drip tray so the soil doesn't reabsorb it. Peaces lilies sometimes come in pots wrapped with decorative foil. The foil traps moisture, so it requires removal after each irrigation.
Irrigating During Flowering
Flowering occurs during the spring and early summer. Peace lilies require more water during this period to help support the flowering stems and blossoms. Depending on the size of the plant and the quality of the soil, the peace lily may need watering two or more times during a seven-day period. Watering when the soil surface feels dry until the excess drains from the pot provides the even moisture amount to sustain blooms.
The peace lily tolerates drier soil when it's not in bloom. The soil can't dry out completely, as the evergreen foliage still requires moisture to survive, but slight wilting when its not flowering usually doesn't harm the plant. Peace lilies generally need weekly watering. Irrigating the soil when the top inch begins to feel dry prevents overwatering. Too much water is more damaging to the peace lily than too little. If the plant does begin to wilt, prompt watering helps it bounce back to its prior health quickly.
Elevated humidity levels help keep the tropical peace lily foliage green and vibrant. Many homes become dry during the winter months as air moisture drops in a heated home. Placing the peace lily pot on top of a drip tray filled with pebbles and soil helps raise humidity. The pebbles keep the pot above the level of the water so it isn't reabsorbed into the soil through the drainage holes, while the evaporating moisture provides humidity. Misting the foliage with water every one to two days also helps raise humidity.