Martin Fish on how to grow streptocarpus like an expert
With just simple care, you can produce dazzling streptocarpus
As part of my work as an accredited RHS judge I get to judge the fantastic nursery exhibits at RHS flower shows through the season. Several times this summer I’ve been involved in judging Dibley’s Nurseries and its wonderful displays of streptocarpus. The quality is second to none and I’m always envious of the plants that are always at their best.
For many years I’ve grown a few streptocarpus in my greenhouse at home and although I can’t claim they’re as good as Dibley’s, they do provide a great display of flowers for several months, from May through until late September.
As a pot plant, they’re fairly easy to grow as long as they’re kept constantly moist, not wet and in dappled shade. It’s also important to feed them regularly through the summer with a high potash fertiliser to keep them flowering, but probably the most important thing to do is deadhead and remove old flowering stalks as often as possible. If you don’t, the plants simply stop flowering.
My plants are now starting to look a little tired and although I could probably keep them flowering for a while longer, I feel it’s time to put them to bed for the winter so they can have a rest. The first stage is simply removing all the flowering stalks by cutting them back as close to the centre of the plant as possible. For this you can use a garden knife or secateurs, but I find a narrow pair of snippers is ideal as you can get right down to the base of the stem. Any damaged leaves can also be trimmed back to the stalk, but the bulk of the foliage will remain on the plant.
Back on the greenhouse bench the plants will be kept just moist and ticking over. They may produce a few small flowers and these should be removed.