African violets are easy to grow but do have specific growing requirements. The first thing to look at is how they are planted. Many that you buy are planted too deeply in their containers. African violets are very susceptible to Crown Rot fungus if the soil is piled up around the base of the plant leaves. We recommend repotting them into new pots, so you can plant them at the proper depth. Drainage is important, so choose pots with drainage holes and use a light potting soil.

African violets are low maintenance plants, but they need good light to continue blooming. To bloom, they need 8 to 12 hours (up to16 hours) of light and 8 hours of darkness per day. For best growth and flowering, African violets require bright light, but no direct sunlight. Direct sunlight can cause leaves to be pale or yellowish-green and flowering will cease.

African violets can be watered from the top or from the bottom of the pot, when the soil surface is dry. Do not let the pot bottom set in water for any length of time! Always use room temperature water because cold water that touches the leaves can cause yellowish rings or streaks on the leaves. Apply a water soluble fertilizer at ¼ the recommended rate every time you water.

Pests aren’t usually a problem, as long as there is good air circulation and the plants are not overwatered. You can use insecticidal soap to control most insects and mites. Mealybugs can be controlled by using a swab dipped in alcohol to touch each insect. 

Additional Resource
http://edis.ifas.ufl.edu/mg028