The most challenging aspect of growing African violets is the inevitable encounter with pests or disease. African violets are affected by common house plant pests, molds and fungus. Some cultural problems can produce symptoms similar to those of infestation or disease – therefore, proper identification and diagnosis are essential to determining a course of treatment.
House Plant Pests
The most common African violet pests are thrips, soil mealy bugs, foliar mealy bugs, cyclamen mites, broad mites, root nematodes and fungus gnats. Mites are the most troublesome since they can spread rapidly through an entire African violet collection and cause twisted, distorted growth. They are very difficult to control and require the use of specially formulated miticides such as Avid® which are very expensive and toxic to humans and animals. If you are reluctant to use harsh chemicals visit your local ‘green’ grower or hydroponics supply store for environmentally-friendly, all-natural pest-control solutions.
Powdery Mildew, Plant Mold and Fungus
Plant molds, such as powdery mildew, and fungus are common problems and easily treated with fungicides and adjustments to culture. African violets are most susceptible to molds and fungus when subjected to fluctuating temperatures or cool, damp conditions. Sufficient air circulation is necessary to keep molds and fungus at bay and your African violets will reward you for providing it. Installing a fan or two in your growing space will help as will remembering to close windows in the evening.
Root Rot, Crown Rot
Root rot and crown rot are common problems for the African violet grower and in many cases can be avoided through proper culture. The most common cause of rot is keeping the plants too wet or letting water sit in the crown. If you wick your plants or grow hydroponically you should monitor them closely to find the right medium to keep the plants from constant wetness. If mold or fungus do take hold they can often be treated successfully with natural products such as neem oil or sulfur-based powders.
Plant Pest Resources
Additional resources for help in diagnosing and treating African violet pests and disease: