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.
Baron Walter von St. Paul is credited with bringing African violets to Europe from West Africa in the late 18th century. He sent samples or seed home to Germany, and by the early 1900s they were blooming in Europe and around the world. The development of hybrid varieties with violet, purple, and blue flower colors in the late 1920's by the Los Angeles nursery of Armacost and Roysten increased the popularity of African violets. Since the 1920's hundreds of cultivars have been developed with an immense variety of flower and leaf colors, shapes, and sizes.
Currently available flower colors include blue, purple, red-violet, orchid, lavender, red pink, white, and bi-color or multi-colored. There are single, double, semi-double, star-shaped, fringed, and ruffled flower types. Leaf types include plain, ruffled, fringed, scalloped, spooned, pointed, and variegated.
The American Violet Society has four classes based on plant size:
- miniature (less than 6 inches in diameter)
- semi-miniature (6 to 8 inches)
- standard (8 to 16 inches)
- large (over 16 inches)
While African violets are relatively easy to grow, they do require consistent care and attention to light, temperature, watering, and fertilization.
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. Learn more about providing supplemental light for African violets in this article: Growing Indoor Plants Under Supplemental Lights.
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 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.
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.
A loose, porous, fertile soilless mix is recommended for growing African violets. Many commercial soilless mixes are available and suitable for African violets.
If flowers fail to form, it is typically because of low light, low temperatures, or improper fertilization. To address low light, move to a brighter location or consider using supplemental light sources. Be sure temperatures are in the 65 and 80°F range and increase temperatures if lower. Both too little or too much fertilizer can cause a lack of blooms. If you are not fertilizing regularly, begin a fertilization routine. Excessive fertilization leads to vigorous vegetative growth and poor flowering.
Pale or Bleached Leaves
Leaves that become pale or bleached in appearance typically occur when plants receive too much light. Move to a lower light situation or increase the distance between a supplemental light source and the plant's leaves to reduce light intensity.
If water is allowed to sit on leaves, it will often cause discolored spots to form, especially with cold water. Water plants from underneath by setting the plant in a tray of water and allowing the water to be drawn up from the bottom. Remove the excess water in the tray once the entire root ball is saturated.
Neck or Stem Forming
As African violets grow, lower leaves die and fall off. Over time this can lead to a long stem or neck that elevates the crown of the plant well above the soil line making it less attractive and more easy to topple. To eliminate the neck, simply repot the plant and set it low in the container burying the stem all the way up to the lowest set of leaves.
Crown rot is a common fungal problem of African violets that are overwatered or recently repotted. Crown rot causes the main stem and lower leaves to appear water-soaked, shrivel, and die. Crown rot usually leads to plant death. Allowing the top of the soil to dry completely between watering will prevent crown rot.
Leaves infected with powdery mildew will have small circles of gray or whitish powder on the topside of the leaves. Control for powdery mildew requires the removal of infected leaves and spacing plants out more for better air circulation between plants. Powdery mildew tends to be more of a problem on plants that are overcrowded.
Mites are small spiders that attack the undersides of the leaves, new growth, and flowers. Small webs are normally found around the leaf axils (junction of leaf petiole and main stem). Mites are so small they are not visible to the naked eye and the damage to the plant is often noticed first. Control of mites may require isolating the infected plant and spraying it with soapy water or a miticide.
Mealybugs are whitish and often exude a "cottony mass" of sticky material for protection. The white cottony masses are easy to spot on the upper and lower sides of the leaves. Control requires soapy water baths or the removal of the bugs with alcohol-dipped cotton swabs.
African Violets are easy to propagate via leaf cuttings. Learn more about propagating by leaf cuttings in this article: How to Propagate Houseplants by Leaf Petiole Cuttings
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