Indoor plants help beautify the home, especially in winter! The African violet, known botanically as Saintpaulia, is one of the most popular flowering houseplants. African violets are easy to grow, yet offer a wide range of cultivars to satisfy the serious grower. African violets adapt well to typical growing conditions found in the home. Because of their small stature, they also adapt well to limited space gardens such as those in apartments with just a few windowsills.
Many cultivars of African violets are available, ranging from miniatures (plants 6 inches or less in diameter) to large (over 16 inches in diameter). Flowers come in blue, purple, lavender, pink, red, and white as well as bi-colored and multi-colored forms. Flower shapes also vary from single, star-shaped blooms to double, semi-double, fringed, and ruffled. Even the leaves come in different types, including ruffled, scalloped, quilted, and variegated. For more information about the various classes and cultivars of African violets, contact the African Violet Society of America (http://www.avsa.org/ Home.html).
Proper light is a necessity for good bloom. African violets need more light than most growers think. Thin, dark green leaves and long petioles (leaf stems) indicate that the plant is getting too little light. Too much light results in stunted plants with short petioles and small, crinkled, and leathery leaves. Avoid putting African violets in direct sunlight, which can yellow and burn the leaves. A window facing north or east is usually the best, especially during the summer. For more even growth, turn the plants occasionally so different sides face the light. Most violet fanciers find plants grown under artificial light will flower more profusely. If fluorescent light is the total light source, the violet will require approximately 600 foot-candles of light for 15 hours per day. Two 40-watt fluorescent tubes suspended 12 to 15 inches above the plants will provide 600 foot-candles of light. For best results, use the wide spectrum fluorescent tubes. However, regular tubes plus one or two incandescent bulbs will suffice.
Whether you use artificial light or not, remember both the intensity and the length of light are important. The closer the plant is to a light source, the greater the intensity. Also, the longer the exposure period, the greater the total amount of light.
African violets grow best at a 65° to 70° F night temperature, with a 10° to 15° increase during the day. To guard against night chilling, remove your violets from the window at night, or put paper between the plants and the window. Chilled violets turn dark within 24 hours, become water-soaked, then wither. If the temperatures are higher than 70°F, light conditions should be near optimum, and a higher humidity is desirable. If temperatures exceed 80° F, growth and flowering will be slowed. Air-conditioned rooms are especially beneficial.
High humidity is beneficial. Homes with humidifiers and basement growing areas are well suited for violet culture. Individual potted plants can be placed on a metal or plastic container filled with gravel, perlite, or sand. A shallow layer of water for evaporation in the atmosphere can be maintained in the container bottom. However, do not set the bottom of the pot directly in the water.
Soils for growing African violets need to remain loose and well-drained for several years. Thus, most garden soils are unsatisfactory when used alone. High organic matter is recommended. Sphagnum peat moss is the best source for this. Excellent plants may be grown in a mixture of soil, sphagnum peat, and perlite (1 part each by volume). Totally artificial mixes such as sphagnum peat moss and either perlite, vermiculite, or calcined clay can also be used. The soil mixture should also be slightly acidic (pH 6.0 to 6.5).
African violets can be grown in nearly any container as long as it has drainage holes. When potting, the soil moisture should be just moist enough to squeeze together slightly. Fill the pot, carefully centering the plant in the soil mixture. Firm the soil carefully, but allow at least 1/4 inch for top watering. Position the plant crown slightly above the rim of the plant. Use foil or some tape along the rim of a clay pot to keep the leaf petioles from rotting. Plants should be shifted to larger pots as they grow. Fewer leaves are broken if the plant is allowed to wilt slightly before repotting.
The amount of water and frequency of watering will vary according to the soil mixture used, size of the pot, drainage, and the environmental conditions under which the plants are grown. Both over-watering and under watering can injure roots.
Watering methods for African violets are a source of controversy. Any method which maintains an adequately moist soil is satisfactory. Keep the crown dry, keep cold water off the leaves, and use room temperature water. Watering from the top is the easiest way to give your plants the moisture they need. Apply water to the surface of the soil until it starts to drip out of the drainage hole at the bottom of the pot.
To water from the bottom, fill the saucer under the pot with water and let stand until the soil surface becomes moist, then drain off any excess water. Whether watering from the top or bottom, wait until the top inch of soil feels dry to the touch before watering again.
However, when plants are continuously watered from the bottom, salts tend to collect on the top of the soil. The concentration of salts may become high enough to injure the plants. Flush with water from the top about once a month to prevent salt accumulation.
Over-fertilization is usually a bigger problem than under-fertilization. The plant itself will determine the degree of fertilization necessary. If the growth rate decreases and the leaves gradually become lighter green, fertilizer may be needed. During the winter months, fertilization can be omitted, unless the plants are grown under artificial light. During the active growing season (spring, summer, and fall), any complete, water soluble fertilizer, applied as directed on the label, can be used; one formulated for blooming houseplants is preferred.