It would be hard to find a gardener who hasn’t grown tuberous begonias at some point in his or her career. Hugely popular and more widely cultivated than the other 1,300 Begonia species and their cultivars combined, tuberous begonias are rightly famous for their ability to brighten up the shadiest corners with their extravagant blooms in a rainbow of colours.
A relative newcomer to Western gardens, it wasn’t until the 1860s that Devon, England, gardener Richard Pearce (b. 1835) travelled to South America on a plant-hunting expedition, returning home with three new begonia species: B. bolivensis (T), B. pearcei (T) and B. veitchii (T), all of which produced tubers. By crossing these species, the first tuberous begonias were hybridized in the late 1860s, and gardeners have never looked back. Sadly, Pearce died of yellow fever in Panama City in 1868, and didn’t live to see the fruits of his labours. Another species, the fragrant hollyhock begonia (B. gracilis [T]) from Mexico was later used as a parent plant in various breeding programs.
This new race of flowers became known botanically as B. ×tuberhybrida, but recently taxonomists have abbreviated this rather long specific epithet by adding (T) at the end of the botanical name to indicate tuberous types.
Most of the potted tuberous begonias we see for sale at nurseries in early summer have been grown from cuttings, and don’t have time to produce a tuber during our comparatively short growing season; as a result there’s nothing to store over winter, and new plants have to be purchased each year. I prefer to buy large tubers of named cultivars in spring, start them off indoors and move them outside once the weather has warmed up. After the first light frost in autumn, the tubers are dried and stored in the basement, ready for the following year. Although big, high-quality tubers are more expensive initially, if they’re properly cared for they will last five years or more, making them more economical in the long run.
Main image: Sunrise begonia courtesy of Tulip World