Rotting Leaves on African Violets

Botrytis Blight

• This fungal infection first appears as wet spots on the undersides of African violet leaves. These grow into soft patches of tissue and eventually form a fuzzy, gray coat of fungal threads. Botrytis blight is caused by wet foliage and hot, humid conditions with little air movement. It can also be caused by cyclamen mite infection. Keep your African violets at a temperature of between 65 to 70 degrees Fahrenheit at night and up to 80 to 85 degrees during the day. Increase ventilation during the summer by placing them close to an open window.

Crown and Root Rot

• The growing crown and roots of African violets are vulnerable to rot if the plants receive too much water. Symptoms include mushy, blackened tissue at the crown and soft roots. Older leaves tend to wilt and drop off. Only water your plants when the surface of the soil is dry to the touch and never leave your African violets standing in a dish of water. When repotting, always plant them at the same height that they were at in their original container as deep planting causes crown and root rot.

Cyclamen Mites

• Tiny cyclamen mites feed on the sap of African violet stems and buds close to the soil line. They cause disfigurement and leaf drop and rot from the center of the plant outward. Treat mites with a commercial miticide spray and by moving your plants to a less humid environment. Discard infected plants that do not respond to treatment and sterilize all pots and tools before using them for African violets again by dunking the pots and tools in a mixture of 10 percent bleach for half an hour.

Petiole Rot

• African violet leaves and stems are easily damaged by fertilizer salts which build up in the soil and in clay pots. Leaf stems of petioles will rot away where they touch the rims of clay pots containing salts. Treat the problem by lining the rims with aluminum foil or tape or by growing violets in plastic pots. Flush out the soil of your plants with abundant water as soon as you see any sign of a white crust or deposit on the soil surface or pot.