Streptocarpus or cape primrose is a relative of the African violet. It is a compact plant with hairy leaves. It can grow to be 12 inches tall and produce 2-inch wide trumpet-like blossoms of red, pink, blue or purple on a 6-inch flower stalk. Streptocarpus blooms nearly all year long if you remove the flowers that have started to fade before seeds develop.
Light and Temperature
Streptocarpus likes medium, indirect light. Streptocarpus requires cooler conditions than normal temperatures indoors. They prefer range of temperature is above 55 degrees F and below 75 degrees F. They like a cooler night time temperature than the temperature during the daytime.
Streptocarpus should be grown more dry than wet. The soil should be moist not water logged. Never allow streptocarpus to sit in water. After flowering, let streptocarpus dry out a little so it can rest a bit. In the wild, streptocarpus often recovers from drought conditions but not from floods. Irrigate streptocarpus with room temperature water. Cold water will leave marks on the leaves.
Plant streptocarpus in an African violet soil mixture in a shallow container. Transplant the cape primrose when only necessary. To make your own soil, mix together 1 1/2 part peat moss, 1 part perlite and 1 part vermiculite.
Fertilize your streptocarpus twice a month with African violet fertilizer or with bonemeal. If you use a high phosphate fertilizer, then fertilize once a month. Streptocarpus will blossom if not fed, but the color will not be as intense as a well-fed plant.
Streptocarpus does have a few unique problems. Exposure to too little light will cause the leaves and stems to be limp. If the leaves are wilted and turning yellow then the streptocarpus has been over watered and is suffering from root rot. Dry the soil out when attempting to save it. Streptocarpus can become infested with mealybugs. Use insect spray developed for houseplants to get rid of the mealybugs.
The main method of propagation is through leaf cuttings. Select a large healthy leaf and cut it down the center. Remove the leaf rib. You should have two pieces of leaves cut crossways. Moisten some African violet potting mix and stand the leaf pieces in it in an upright position. Make sure the cut edges are under the soil. If you want to give your cuttings a boost then dip the cutting edges in rooting hormone. Streptocarpus can also be propagated by division in the spring.