Streptocarpus is a relative of the African violet and a perennial native to South Africa. It can be difficult to provide ideal growing conditions for it. Streptocarpus are typically grown as houseplants, because they cannot survive even mild winters outdoors in most climates. The plant forms large, bell-shaped flowers that come in a wide variety of colors. Different species and cultivars of streptocarpus flower during different times of the year.
Keep streptocarpus at a minimum temperature of 50 degrees F year-round. They do best at temperatures between 65 and 80 degrees. Bring potted plants inside for the duration of the winter. Discard outdoor streptocarpus that have been exposed to temperatures below 50 degrees for long periods of time, as they will not be able to recuperate in the spring.
Plant streptocarpus in a fertile, well-draining soil made of one part sphagnum peat moss, one part vermiculite and one part perlite. Use a wide, shallow planter to prevent the roots from becoming too wet. Place the container in an area where the plant will receive bright, indirect sunlight for several hours a day.
Water streptocarpus once per week using room temperature water. Apply the water evenly, and allow the soil to dry out completely between waterings. Never allow the soil to get soggy, as root rot can occur.
Feed streptocarpus plants once every two weeks using a liquid fertilizer with high phosphate content, such as a 13-40-13 formulation. This will encourage the growth of flowers over foliage. Feed only from April till September, and mix the fertilizer to half-strength before applying.
Use a humidifier to add additional moisture to the air surrounding indoor streptocarpus. Do not mist the foliage to increase humidity, as fungal infestations can occur if the leaves are damp for too long.