The best way of starting a collection of streptocarpus plants is to raise them from seed, which is easily obtainable. Plants can be raised from seed without difficulty, whether you possess a greenhouse or not, because seed can be sown at any time between midwinter and mid-summer. Seed sown in mid-winter in a temperature of 68 - 78°F (20 - 25°C ) should produce flowering plants in summer. Alternatively, seed may be sown in early summer without heat to produce flowering plants for the following year. If you can it is better to sow seeds in mid-winter, because not only will these produce plants which will flower the first year but by the following year they will be much larger plants and will usually provide a continuous mass of flowers from mid-summer until early winter. The seed should be sown on the surface of a soilless seed compost and, either pressed into the compost, or covered very lightly with a fine sand. If you decide to press the seed into the compost, use an implement to which the seeds will not adhere and, after completing the operation, wet the surface slightly with water, by means of a fine spray, which will help to bed the seeds down in the compost. Enclose the seed pan in a plastic bag until the first signs of germination, which should be in 12-14 days if the temperature has been between 68 and 78°F (20-25°C ) .
The seedlings should then be pricked out into 4 1/2-in (11.5-cm) half-pots as soon as they are large enough to handle - the sooner the better - using compost E6. The seedlings are very slow-growing but when they are about three months old should be large enough to pot into 2'/2-in (6-cm) pots in compost E6. Potting on is only necessary when the pots are full of roots, and this will vary from plant to plant, but the size of the top growth is usually a good indication. When the plant has made good leaf growth it is time to look at the root growth. Your plants are not likely to require larger than З 1/2-in (9-cm) pots during the first year, from seed sown in mid-winter to early spring, but the following spring should be ready for potting on into 4 1/2-in (11.5-cm) or 5-in (13-cm) pots. Be guided by the size of the plant and the amount of root growth both for when to pot and for the size of pot to use.
