Are African Violets right for you?

By Melanie Mathieson
Gardening Guru

Many of the house plants and annuals available here in our gardening zone, are plants that grow in the wild or as perennials in a much warmer climate. One example of this is the African violet, a popular house plant well suited to growing in pots in homes in Canada that is native to the wild in Africa.
The African violet (Saintpaulia species) is a popular houseplant because it grows and flowers under natural or artificial light conditions found in the average home. Many different varieties, types and flower colours, that range from white, pink, lavender to vibrant purples, exist.
Drainage is one of the most important considerations in choosing or preparing a soil mixture for African violets. Pre-packaged African violet soil mixes are available or you can mix your own with equal parts of peat moss, vermiculite and perlite. Any pot is suitable as long as they have drainage holes. African violets should not be watered only as needed because their water needs vary with soil mixture, drainage, light, temperature and humidity. Plants in clay pots require more frequent watering than those in plastic pots since evaporation is greater. In general, water African violets whenever the soil surface feels dry to the touch, but before it becomes hard or the plant wilts. African violets may be watered from the top or bottom. When watering from the top, apply enough water to thoroughly saturate the soil and discard excess water that drains through the bottom of the pot. Make sure the temperature of the water is the same or slightly warmer than that of the room. If cold water touches relatively warm leaves, it will cause yellowish spots or streaks on the upper leaf surfaces. Self-watering pots are suitable for your African violets as well. Violets can also benefit from watering from the bottom, by placing the pot in a container to which about one inch of water is added. When the soil surface becomes moist, remove the pot, allow it to drain, and pour out the excess water. Just remember that the violets should occasionally be watered from the top to flush accumulated fertilizer salts from the soil.
For best growth and flowering, African violets require bright light, the amount of light within 3 feet of a southeast or west facing window, but no direct sunlight. The appearance of a plant will indicate whether light levels are too high, too low or just right. If light is too low, leaves are usually thin and deep green, and appear to reach up for light. The plants may grow, but will flower poorly or not at all. In such instances, supplemental artificial light will help promote flowering. Excessive light causes leaves to be pale or greenish-yellow. Some leaves may show dark green areas where they have been shaded by upper leaves. Growth slows when light is too high and plants become very compact. Flowering will also begin to decrease.
Growth and flowering of African violets is also affected by duration of exposure to light and darkness. To bloom, they need 8 to 12 hours (up to 16 hours) of light and 8 hours of darkness per day. A plant that gets the right level of light but for too short a period of time will do poorly compared to a plant given weak light for a long period. Where natural light is unavailable or reduced, African violets can be grown under artificial light. Incandescent light may be used, but fluorescent lamps give better results.
African violets prefer a night temperature of 65-70 degrees Fahrenheit, but will grow satisfactorily at 60 to 80 degrees Fahrenheit. Under prolonged high temperatures, growth and flowering is reduced. During hot weather, place plants in the coolest place in the home or in an air-conditioned room. African violets grow best in high humidity, which can be achieved by setting pots in water-tight metal or plastic trays filled with pebbles and water. Avoid placing pots directly in water to prevent root damage.
Water-soluble fertilizers such as 20-20-20 or 15-30-15 are commonly sold for use on African violets. Mix the fertilizer in water at one-fourth the recommended rate and apply it each time you water. Soil should be moist before dissolved fertilizer is applied. Discard excess water and fertilizer solution that drains from the bottom. A gradual loss in leaf color combined with reduced growth and flowering usually indicates that the plant needs fertilizer. If in doubt, fertilize one or two plants and wait ten days to see if you see a reaction. If plant growth is evident and the leaves become darker in color, fertilize the rest of the plants, too. When over fertilized, African violets develop tight centers and the new leaves take on a rusty appearance.
African violets are easily propagated by leaf cuttings by selecting a healthy and firm leaf from the middle of the plant and snapping or cutting it off at the stem but leaving the petiole (leaf stem) intact. The petiole should be trimmed to about 1-11⁄2 inches in length. Insert the petiole into a hole made with a pencil or similar tool, into a combination of half vermiculite/half sand or half vermiculite/half potting mix. Roots normally form at the petiole base in three to four weeks and leaves of new plants appear three to four weeks after roots form. Plants will begin flowering six to nine months later. Multiple crowns can be carefully divided and each planted into new pots. Older, “leggy” plants can be successfully rerooted by cutting the plant off at the soil level and then repotted so that the leafless stem is positioned below the soil line, where it can grow new roots.
Although I have never had any problems with African violets, various diseases can affect them. Adequate spacing in the pot, use of sterilized soil and prompt removal of faded flowers and unhealthy leaves will really help prevent disease problems. Here are a few tips if you encounter any of the following:
Mealy bugs and cottony egg masses can be controlled by mixing alcohol with an equal amount of water and touching each insect or egg mass with a cotton swab dipped in the solution.
Any other insects and mites can be managed with insecticidal soap sprays.
Cyclamen mites cause severe stunting of plants and are very difficult to control. Unfortunately, the best management strategy for this pest is to discard affected plants.
Root diseases are usually caused by over-watering. The first sign of this problem is usually a limp, unthrifty plant. In most cases the plant should be discarded.
Petiole (leaf stem) rot occurs when petioles touch the edge of the pot and develop brown, sunken areas at points of contact. This injury is caused by fertilizer salts that accumulate on the rims of clay pots. Petiole rot can be avoided by waxing the pot rim, covering it with aluminum foil or repotting to a larger pot.
Now that you are aware that an African violet could be a perfect houseplant for you, look for them in the local nurseries (that sell houseplants) and flower shops this time of year.