Streptocarpus: Greenhouse Plants
W – warm, minimum of 13°C (55°F) / T – tropical, minimum of 18°C (65°F)
There are basically two types of these; all the South African and some of the East African species are stemless; this includes the modern hybrids such as S. ‘Maasens White’ most of which derive from Streptocarpus rexii. All those species from West Africa, Madagascar and Asia with a few in East Africa are caulescent, which means they have a proper stem structure rather than growing from rosettes of leaves or even single leaves. Most of the plants we grow are the hybrids which come in a great variety of different coloured and marked flowers including some with yellow marks. They hate to be overwatered and grow best in a light peaty. They will tolerate lower temperatures providing they are kept on the dry side. They will stop flowering if temperatures drop below 13-15°C (55-60°F) for any length of time, only starting up again when those temperatures are restored. They like the air of the greenhouse to be humid which will stop them from becoming brown at the tips of the leaves as will attention to shading in summer. Water must be kept away from the soft leaves otherwise they are disfigured by scorch marks.
Propagation is byor by seed surface sown in March or April and germinated in a light place at 13-18°C (55-65°F). Some of the species are great fun to grow if you can find them. I like S. saxorum from East tropical Africa which is a stem forming species with small fleshy, almost succulent leaves and delicate pale lilac flowers held away from the plant on straight stalks. S. grandis from Natal is incredible, producing one 60-90-cm (2-3-ft) long stemless leaf which can be over 30 cm (1 ft) wide. Flowers are pale purple and white. In cultivation it is a challenge to grow this without the leaf going brown at the end and not reaching its full length.