African Violet Care
African violets are one of America’s most popular houseplants. They belong to the Saintpaulia genus and are one of the most commonly grown members of the gesneriad (Gesneriaceae) family. They are not related to the hardy violets (Viola) we enjoy in outdoor gardens. Under the proper growing conditions, they will bloom almost continuously indoors.
While African violets are relatively easy to grow, they do require consistent care and attention to light, temperature, watering, and fertilization.
Light
Proper light is essential for good bloom. African violets require more light than most gardeners first realize. Thin, dark, blue-green leaves with long petioles indicate insufficient light. However, direct light for long periods can be damaging. Too much light produces stunted plants with leaves that are small, crinkled, leathery, and yellow. Generally, windows with north and eastern exposures are best for African violets. Plants also grow well under fluorescent or LED lights. Place lights 4-8 inches (yes, that close!) above the plants for 12-16 hours per day to provide sufficient light to initiate blooms.
Temperature
African violets require air temperatures between 65 and 80°F. Typically, temperatures below 50°F will cause leaves to darken, wither, and become watersoaked. Temperatures above 85°F will slow growth and flowering.
Watering
Watering African violets is often the most difficult part of their care. The plants require a moist, well-drained soil. If the soils are too wet, the plants may rot. If plants are too dry, growth will be stunted and flowering will be limited. Water temperature becomes especially important during the winter months, as cold water directly on the leaves will damage them quickly. African violets are often sub-irrigated by placing the plant in a saucer of water and allowing the plant to soak up water from the bottom of the pot. This prevents injury from cold water on the leaves and insures moisture throughout the soil. However, plants should not remain submerged in saucers of water for long periods as they may rot. Allow the top inch of the soil to dry before sub irrigating again.
African violets also can be watered from the top of the soil if room-temperature water is used and the foliage remains dry. In fact, occasional top watering is recommended to prevent salt accumulation. Specially designed African violet pots allow continuous watering. A water reservoir at the base of the plant and an absorbent wick, or porous surface connects the soil and the water reservoir. This method is effective in maintaining an even moisture level of the soil.
However, periodic leaching of the soil profile with water from the top might be necessary to prevent the accumulation of salts.
Fertilization
Regular fertilization encourages plants to bloom throughout the year. A complete fertilizer applied at a low rate is best. Excessive fertilization leads to vigorous vegetative growth, poor flowering, and the accumulation of salts in the soil. Plants can be fertilized with special fertilizers formulated specifically for African violets or with a general, balanced fertilizer at 1/2 or 1/4 strength.
Soils
A loose, porous, fertile soilless mix is recommended for growing African violets. Many commercial soilless mixes are available and suitable for African violets.
Source: Cynthia Haynes – Iowa State University Professor and Aaron Steil – Iowa State University Consumer Horticulture Extension Specialist (Iowa State University Horticulture and Home Pest News – January 2023)