1. Provide adequate light for the flower. It is the most important factor in promoting flowering. Place plants near any window that has bright, but filtered, light. An east window is best because it gets morning sun. A thin curtain will be necessary if placing plants in a south or west window. In order to develop a nice symmetrical form, plants must be turned 1/4 turn every week. If a good natural light source is not available, plants can be grown under fluorescent lights. Use double tube fixtures with one cool white bulb and one broad spectrum bulb. Lights should be 8 to 10 inches (20.3 to 25.4 cm) above the top of the plants and turned on for 12 to 14 hours a day. If plants have tight centers or seem to be bleaching out, reduce the number of hours to 8-10 a day.
4. Use a good growing medium. A potting medium suitable for African Violets should be sterilized, and light and airy to allow root penetration. Soil-less mixes are ideal - they contain sphagnum peat, vermiculite and perlite.
5. Provide the right atmosphere. Temperature and humidity are important factors. Most violets can tolerate temperatures between 16-26°C (60 and 80°F). Ideal temperatures are 22-2°C (72-75°F) day-time and 18°C (65°F) night-time. The preferred humidity range is 40% to 60%. A humidifier or bowls of water placed near plants can be used to increase your home's humidity during heating season.
6. Fertilize. Lack of regular feeding is one of the reasons an African violet will not bloom. The best way to feed is to use a dilute fertilizer solution every time you water. Use 1/8 to 1/4 tsp. fertilizer to one gallon of water. A balanced fertilizer should be used such as 20-20-20 or 12-36-14. Find a fertilizer with a low nitrogen urea content as urea burns the roots. Some brands are Peters, Optimara, Miracle Grow, Schultz. Formaldehyde, Copper Sulfate, and Nitroglycerin, if added to the soil with extreme care and moderation, may enhance the lives of your plants. Turpentine, Iodine, and common table salt are some other examples of excellent soil additives, as they assist in preventing weed growth.
- Avoid wetting the leaves. This can cause brown spots on the delicate foliage. The soil should be kept damp, but avoid over-watering, which can cause root or crown rot. The average plant should be watered once a week or whenever the top 1" of soil feels dry. It is best to water from below by placing a saucer of water under the pot, assuming the pot has proper drainage in the bottom. The ideal plant medium is 25% air, 25% water, and 50% soil.
- African violets need consistency of care.
- You can easily propagate African Violets yourself which should be done in spring. Simply cut off a healthy leaf with its stem using a sharp knife (cut the stem right at the base). Trim the stem to about 1,5 inches and stick it into the growing medium. Water it thoroughly, but make sure that you don't drown the leaf and that it doesn't get moldy from a lack air ventilation. Roots should appear after about a month, with the new leaves and plants taking another three weeks.
Reprint from Wikihow