Mold That Affects House Plants

Identification

• Quite a few houseplants are susceptible to gray mold caused by Botrytis cinerea, but the disease is more common on plants that are growing in overly humid conditions. Keeping plants in areas with poor air circulation and overwatering are also among the common causes.

Damage

• The condition is characterized by the appearance of brown, water-soaked spots on plants. Affected tissues gradually turn soft and watery. Infected plants start to wilt. A mat or mold composed of fine, gray-brown, fungal threads starts to grow on infected tissues. Flat, black fungal fruiting bodies called sclerotia are embedded in rotting plant tissues.

Control

• Reduce irrigation in plants and move them to areas with brighter light and good air circulation to reduce humidity. Prune and remove all affected plant areas.