Streptocarpus saxorum: False African violet, Cape primrose.
Streptocarpus and I have an on/off love affair. I buy them from the garden centre looking fresh and full of promise; sometimes they stay that way until the fatal day when I give them a drop more water than they would like. Then, taking no account of the months, occasionally years of TLC I have bestowed upon them, they go terminally limp and refuse to recover.
I now operate a strict once a week watering regime, allowing the plants to become completely dry between soakings. This works until a house guest or the cleaner takes pity and administers a deadly dose of H2O. Being creatures of the woodland floor streptocarpus dislike drafts and direct sunlight as much as overwatering. So, unless you are very green fingered, or live in the Drakensberg Mountains from whence they hail, you are going to need to make an effort to keep them alive.
My experience is that streptocarpus will let you know when they are happy. My finest specimen, a hybrid called ‘Albatross’, lives on the sill of a north-facing window in a spare bedroom. I visit it to water and deadhead once a week and in return I get a long succession of white flowers with acid-yellow throats. The leaves occasionally grow so long that they hang half way down to the floor. I dare not move it as even the slightest change of environment has put paid to other cherished plants.
I thought all Streptocarpus required mollycoddling until I stumbled upon Streptocarpus saxorum. In truth I didn’t know what I had stumbled upon for about three years as I couldn’t identify it at first. Every summer I would stay in a German castle on a business trip, and there the window boxes in the courtyard would be filled with a plant possessed of soft, felted, green leaves, bearing lilac flowers on long wiry stems. They had the appearance of little butterflies fluttering in a breeze.
Fast forward to spring 2015 and I spotted pots of the very same plant at our local garden centre, tucked away on the bottom shelf of a Dutch trolley. I snapped them up, took them home and then worried about what their identity might be. I eventually established they were Streptocarpus saxorum, which by forming leafy stems rather than sprouting from a basal rosette makes them streptocarpellas rather than a streptocarpus. To me, both sound more like bacteria than flowering plants.
Recalling the ideal conditions at the German castle, I planted my streptocarpellas in window boxes and placed them on the outside sill of our neighbour’s garage window. There, sheltered and shaded from the sun for all but an hour every day they have prospered, quietly forming bushy plants attended to by a troupe of dancing butterfly blooms. Like my indoor streptocarpus they are watered just once a week by me, and by rain in between times. Apart from that they seem easy going and disease free. Even snails don’t seem especially interested.
I will take cuttings before the winter sets in, as the plants are not frost hardy. In the meantime all I have to do is deadhead regularly and feed with a high potash fertiliser every fortnight.
Streptocarpus saxorum is a wonderful choice for windowboxes or containers in cool, shady areas and deserves to be more widely grown. Unlike its indoor cousins it is no trouble at all.
Streptocarpus saxorum is available from Dibleys Nurseries, holders of the National Collection of Streptocarpus.