PICK OF THE VERY BEST: DIASCIAS
Sun-loving favourites that are equally good in containers
FIFTY years ago, hardly anyone grew diascias. But when the nurseryman and Gardeners’
World presenter John Kelly introduced ‘Ruby Field’ in the early 1970s, gardeners started to take notice.
Diascias are dwarf, often trailing or sprawling, sun-loving annual and perennial plants from south-east Africa. Resembling a more delicate-looking snapdragon or nemesia, they have a very long summer flowering season.
Spikes of small, open-mouthed flowers are carried on slim (but often wiry) stems, and come in a huge range of red, pink and sometimes purplish shades, as well as white. There are also a number of fine varieties in orange and apricot shades that are relatively hard to come by in summer flowers, and the blooms are set against small heartshaped or linear leaves.
One of the reasons that diascias have such a long flowering season is that the flowers are specifically adapted for pollination by a particular species of South African bee – other bees just can’t do the job. And because we do not have that kind of bee here in Britain, the flowers are never pollinated so the plants just keep on blooming.
Diascias range from hardy – albeit often short-lived – plants for sunny and well-drained summer borders, to more tender varieties that are best treated as summer patio plants. It’s as patio plants that most recent developments have taken place. New varieties of these have
come thick and fast, with the result that the RHS has not yet had the chance to assess them for awards.
Here we’re focusing instead on the AGM-winning varieties among the hardier types – there are 17 in total. Lovely at the front of a well-drained sunny border (or tumbling over the edge of a raised bed, perhaps), these hardy types can also be grown in containers as long as the drainage is good.
Some, including D. rigescens, spread steadily at the roots to fill in around bushier, more substantial plants. They’re a doddle to propagate: simply split and replant as they start to grow in spring; don’t leave it too late or divisions may fail to establish. All will root easily from short new shoots in spring and summer.
Diascias are lovely with dwarf, sunloving shrubs such as lavenders and perovskias, filling in around their woody stems. Meanwhile, their loose growth allows autumn flowers like colchicums and shorter Michaelmas daisies to peek through. If you have a sunny corner in your garden, give them a try.