Streptocarpus ‘Constant Nymph’ was only a by-product of Lawrence’s scientific journey of discovery but it launched a new horticultural industry.

Streptocarpus will develop trumpet-shaped flowers from late spring onwards, sporting many different colours depending on your chosen cultivar. The individual inflorescence will last around two weeks with the overall show lasting two or three months. Scroll up to 'Dormancy Care & Annual Flowers' for more information on achieving yearly blooms.From 1929 Lawrence was helped to make thousands of pigment identifications by a biochemist, Rose Scott-Moncrieff, who had begun to look into the chemistry of flower colours in the plants under investigation at John Innes. I grow them as ground covers in large terracotta pots of Camellia azalea at the entrance to our garden room where they charm me every time I walk in. They can take lots and lots of water and rain in summer but prefer to be a little on the dry side through winter. Lynne Dibley was inspired by the John Innes varieties and went on to breed her own totally different style of Streptocarpus – and success followed. Dibley’s released their first variety ‘Crystal Ice’ in 2000 which was awarded the RHS’s Award of Garden Merit in 2001.

During the summer grow them in a shaded greenhouse, indoors on an East or West windowsill or anywhere that is bright but without strong sunshine - early morning or evening sunlight is weaker and therefore ok. During the winter months keep your plants in as bright a position as possible to prolong growth and the flowering season. During winter do not water plants directly after filling a watering can from the tap as the water will be quite cold – fill water in the can or in some container a day in advance so that the plants can be watered with water at room temperature. Propagating Streptocarpus can be a simple and enjoyable hobby. It’s very easy to create dozens of baby plants, increasing your collection and creating new plants for gifts. Cut off a large, healthy leaf with a clean razor blade and slice out the central vein, leaving two leaf halves. Plant the halves in rich potting soil by standing them up with the cut side down. In 1972 John Innes released its first batch of seven new varieties of Streptocarpus named; Diana, Fiona, Karen, Louise, Marie, Paula and Tina through the National Seed Development Organisation (NSDO). Later Brown developed further varieties, both by traditional breeding methods and by X-ray and chemical-induced mutation.

Advice on buying streptocarpus

On our Nursery we use a combination of biological control and a weekly spray SB Plant Invigorator. It must be noted however that biological methods alone may only control pests but not eradicate them. Biological control can be done on an amateur scale in a glasshouse or conservatory. Supplies are available in the UK from: Green Gardener, 41 Stumpshaw Road, Brundall, Norfolk, NR13 5PG. Streptocarpus prefer to be on the dry side and it is important not to overwater them. Over-watering, in particular regular over-watering, will cause harm to the root system. The first symptom of over-watering is the same as under-watering i.e., the leaves will wilt. Streptcarpus or the Cape Primrose forms a rosette of oblong, hairy leaves above which rise large, showy, trumpet-shaped flowers on erect stalks.

While the specimen is budding or in bloom, switch to a product high in potassium to prolong the duration of flowers. Good examples of this are a Dibley's Streptocarpus Food or a tomato-labelled feed. Revert to the original fertiliser once the final inflorescence elapses. Plants can be potted-on if necessary in spring, using a specialist houseplant or multi-purpose compost Place pots in a propagator or cover with a clear plastic bag, and provide bright but not direct light. Keep at 18°C (65°F) This plant loves light, but direct sunlight can burn foliage. A home with an east or west-facing window is perfect, but if a southern view is all you have, you can slip a sheer curtain between the plant and the windowpane to diffuse the worst of the glare. Tips for Growing Streptocarpus Plants

Tips for Growing Streptocarpus Plants

As, Jane says, the Streptocarpus genus falls in the Gesneriad family comprising numerous genera that are relatively little-known but include many types of plants, the vast majority of which bear unusual and attractive flowers. Leaf cuttings are taken in spring or early summer choose healthy younger leaves from the centre of the plant When re-potting choose a pot only slightly bigger than the current one, about a thumb's width wider in diameter, or one 'pot size' larger if using old-fashioned clay pots. A wide shallow pot or half-pot is more suitable than a deep pot.

In spring and summer, you may feed the plants about every three weeks with a houseplant liquid fertiliser. ‘Hope’Knowing their geographical distribution helps in understanding their care. Remember, they naturally come from the wooded areas on mountains, so they do not want full midday sunshine, but instead need a light position. Too much sun burns the leaves and fades the flowers. Leaves rotting at the base is most likely due to wet conditions, such as impeded drainage, over-watering, compost too heavily firmed or the base of the pot sitting in water accumulated in the bottom of the pot-holder. Remove the rotting leaves and allow to dry Next, dip the wounds in a water/bleach solution (9 parts water, 1 part household bleach) to promote sterility. (Only use if you're an adult, following safety recommendations of the manufacturer). While using a seed tray or Bonsai dish and 'Houseplant' labelled potting mix, place the leaf sections wound-down in around 1.5cm (0.6 inches) into the soil. Apply slight pressure around the base of the leaf for extra stability with the sounding soil. Provide a bright, indirect setting with temperatures above 18℃ (64℉) and keep the pot in a sealed transparent bag with multiple small holes to maintain high humidity. Open the bag every couple of days to monitor how the cuttings are performing and to allow fresh air to circulate. Remove any rotten or yellowing material as it can spread onto neighbouring leaves. If propagation is successful, you should start to see new shoots surfacing the soil line after six to eight weeks. Keep the growing conditions the same, and once the shoots are big enough to pot on (four leaves on each growth), they can be potted up in 'Houseplant' Compost with 7cm (3 inch) pots. Repot as necessary and care in the same way as adult specimens with the care tips written at the top.