There are several reasons why Prayer Plant leaves get brown edges and curl. A Prayer Plant likes a very humid environment and the humidity in ours homes is often too low. You can increase the humidity by grouping plants together, putting a small humidifier or bowl of water near the plant, or setting a Prayer Plant on a tray filled with water and small stones or pebbles. Be sure the plant is sitting on the pebbles and not in the water. Other causes are: the leaves of your plant may be touching the cold glass of the window: too much plant food. Prayer Plants should not be fertilized very often since excess plant food can cause brown edges. Always dilute the plant food to 1/2 the recommended strength.