African violets require little grooming. Dust the leaves with a small, soft brush, remove all dead leaves and flowers promptly and remove any offshoots (except in the case of hanging plants). Older plants often have a number of offshoots that interfere with blooming and make them less attractive. An older plant whose leaves are growing high up on its crown may be rejuvenated by repotting it more deeply. Some amateur growers even go so far as to cut the stem off just under the rosette and repot it in a new container, where it will sprout new roots.
Being a tropical plant, the African violet requires high humidity, between 40 and 60%. This may be difficult to obtain, especially in the winter, when houses are heated. The leaves will curl when exposed to dry air and the quality of the blooms will suffer. Using a humidifier will remedy this problem. Another way of providing the plant with the necessary humidity is to place it on a saucer filled with gravel and water.
The frequency of watering will be influenced by the plant’s stage of growth and the soil composition, ambient humidity and amount of light. The plant must be watered as soon as the soil on the surface becomes dry but is still somewhat moist underneath. Add plenty of water, until it seeps through the drainage holes at the bottom of the pot, in order to moisten the root ball thoroughly. After one hour, remove any water still standing in the saucer.
It is important to use water that is slightly warmer than room temperature; cold water will cause spots to appear on the leaves. Moreover, blooms will suffer if the roots are chilled. Morning is the best time to water a plant. Watering at night promotes the development of fungus-related diseases, while watering in the afternoon may cause leaf spots to appear, especially if the plant is exposed to the sun while still wet.
Opinion varies on whether African violets should be watered from the top or bottom. Watering from the top will not cause any problems if the above instructions are followed. Water may also be placed in the saucer to be absorbed by the soil, provided that the plant is flushed from the top periodically to wash away fertilizer salts that accumulate on the surface. The same applies to containers equipped with a wick.
As a rule, it is important to avoid overwatering, so as not to reduce the amount of oxygen available in the soil. This will first affect the roots and then the entire plant. The weight of the pot is a good indication of when water is required.
Fertilizers are an important source of food for an African violet. A balanced formula such as 20-20-20 is suitable during the vegetative period. To flower, the plant requires more phosphorous; a 10-30-20 or 15-30-15 fertilizer is appropriate.
Many people like to fertilize their African violets once a month, following the manufacturer's recommended dosage. Alternatively, 1/4 to 1/5 the regular dosage can be added with each watering, as this causes less shock to the plant. Finally, the plant should not be fertilized if it is dormant or ailing.