One of the first plants I grew, as a pre-teen gardener was a gloxinia. I bought the tuber from the garden/hardware section of Tuttles opposite the station in Lowestoft. I always associate the smell of creosote and jute with gloxinias ever since. I seem to remember that the choice of varieties in those days was pure white, bishops’ purple and red with a white edge and I don’t think things have changed much since then. The only difference is that you don’t often see the tubers for sale – who grows them these days?
Although we call them gloxinias they are actually sinningias. Sinningia is a genus in the African violet family (Gesneriaceae). All 70 species are South American but most are from Brazil and that is where Sinningia speciosa – the wild gloxinia – is native (speciosa means showy). The flowers of the wild plant are like big foxgloves with one lower, big petal but the common gloxinia has rounded flowers with similar-sized petals. The doubles have many more petals in the centre.
As houseplants they have their problems because they are a bit picky about watering and they only flower for a few months. The large leaves are also brittle and the plants need careful handling or they snap off. In theory you can grow them from seed but the seeds are tiny and the seedlings need great care to get them to maturity. You get easier results from tubers but I bought my (seed grown) plant in a supermarket for less than the price of a coffee! Like most tender gesneriaceae they hate cold water and to be standing in water. It is better to let them almost dry out between watering but don’t make a habit of this or they will get mildew and brown edges to the leaves. Although they like warmth (no less than 12c) direct sun is not advised and my plant is happy enough in the north-facing conservatory for now. You should carefully cut off the fading flowers or they will mark and damage the relatively few, hairy leaves. Feeding is advised so they continue to develop all the potential buds. At the end of summer they should be thinking about dormancy so reduce watering and allow them to dry out so the stems drop off the tuber. In theory this can be kept for another year. It is best to keep it in the pot, in a cool but not cold place, with very occasional watering to prevent the tubers dehydrating. Then repot them in spring.
Although rather old fashioned, there is something glorious about gloxinias. The flowers are opulent and velvety and at least they have the decency to disappear for half the year unlike their cousins the African violets that look dejected and sulk as they collect dust and deteriorate!