The Diseases of the Peace Lily

Cylindrocladium Root Rot

• Caused by fungus that appears from overwatering, Cylindrocladium root rot can destroy a peace lily. The disease can travel from plant to plant via water flow, such as when several plants are contained together or positioned closely in a landscape bed. Avoid the disease by only moistening a peace lily's soil with room-temperature water and by allowing the soil to dry completely between watering sessions.

Leaf Spot

• Leaf spot is another fungal disease caused by overwatering. It is a common term that applies to several fungal infections. Symptoms include spotted or blackened leaves. If infected, a peace lily develops spotted leaves that eventually may yellow and fall off the plant. The fungus travels by airflow or splashing of infected water onto foliage. It can be avoided by allowing the plant’s soil to dry between each watering session. Apply water directly to the peace lily's soil, avoiding its foliage.

Spider Mites

• Spider mites can infest a peace lily by laying eggs on the underside of its leaves. The mites feed on sap within the leaves, bruising the leaves' surface and causing the plant's eventual death if they are not eradicated. Spider mites can be transmitted through unsterilized potting soil. They also can be transferred from plant to plant by feather dusters and cloths. Avoid a spider mite infection in a peace lily by keeping the plant in ideal condition with adequate sunlight and water. When a peace lily is weak, it is more susceptible to a spider mite infestation.

Mealybugs

• Mealybugs appear as tiny, white, waxy, raised spots on the underside of leaves and in the area between a leaf and stem of a peace lily and other houseplants. They feed on the inner flesh of leaves and stems, and they stunt or kill the affected plant if not controlled. Mealybugs typically develop before a plant is purchased. Prevent an infestation by inspecting a peace lily thoroughly before take it into your home. Keep a new plant quarantined from other houseplants for seven to 10 days to avoid transferring a mealybug infestation to other houseplants.