How to Make a Streptocarpus Bloom

Place Streptocarpus in bright, indirect light during the summer months, such as an east- or west-facing window. Move them into a south-facing window during the winter months. If you live in the far north, supplemental fluorescent lighting will cause Streptocarpus to bloom virtually all year-round. Use a fixture with two bulbs and situate the bulbs 6 inches above the tops of the plants. If only a south-facing window is available, put a sheer curtain between the window glass and the plant during the summer months, to protect it from the intensity of the summer sun. Light is the most important component for helping streptocarpus bloom. With adequate light they will bloom all year long, even with no fertilization, although their color will fade.

Maintain ambient room temperatures between 50 and 70 degrees F during the day and 45 to 65 degrees at night. Streptocarpus produce flowers more easily in cooler temperatures, so put them in the coolest room in your house.

Grow Streptocarpus in a very light, well-drained potting mix for best results. Mix one part coarse builder's sand with two parts of indoor potting soil for a mixture suitable for growing cape primrose. Mulch the surface of the soil in its pot with sphagnum moss to help keep it cool, especially if the plant is kept outside during the summer months.

Fertilize monthly with a high-phosphate fertilizer. Fertilizer high in phosphorus encourages the production of flowers.