Brown Dry Spots on Peace Lilies

Water

• The type of water you use for watering can cause brown edges on plant leaves. Softened water contains salts to soften it, which may result in an accumulation of salts in the plant and cause burn marks to form on its leaves. Salt build-up can be suspected if you find a white, flaky substabce on the pot or surface soil. Water the plant with bottled drinking water or distilled water to avoid salt build-up. Use water that is at room temperature when watering.

Over-Fertilizing

• Brown, dry spots along the edges of the leaves or scorched leaf tips might also be a sign that soluble salts are accumulating in the plant as a result of frequent fertilization. Peace lilies plants require very little fertilizer. A balanced, liquid houseplant fertilizer such as 20-20-20 diluted at one fourth of the recommended dose applied every two to three months will suffice.

Diseases

• Fungal diseases may be the cause of brown, dry spots on your peace lily plant. These include aerial blight (Phytophthora sp.), in which black or brown dead spots up to an inch in diameter form on the leaf margins and centers; cylindrocladium root rot (Cylindrocladium spathiphylli), a root rot disease which may cause elliptical dark brown spots to form on the leaves and petioles; and myrothecium leaf spot (Myrothecium roridum), which causes brown to black circular lesions to form on leaf margins and centers.

Remedies

• Withhold water to the point that wilting begins to take place. Flush out the excess salts by running bottled drinking water through the soil several times. Make sure the water drains to prevent the roots from sitting in standing water. If the cause of the brown dry spots is from high salt content, future leaves should grow without any marks on them. If the brown tips continue, change to distilled water. Consider repotting the plant in a new container with clean potting material. In the case of fungal diseases, fungicides can be applied.