Digiplexis™, a recent intergeneric hybrid of Digitalis and its kissing cousin Isoplexis (although its DNA analysis may yet put it in the Digitalis genus) bred by Thompson and Morgan UK, has sold out in both the USA and UK this summer. And you can see why…
The Digiplexis™ Illumination™ hybrids seem to combine the best of both genera – they’re long-flowering like an Isoplexis, have tall flower spikes like a Digitalis, and mix the regular cool pink and burnt orange of the two plants beautifully to produce a range of bicolors through to soft apricot. They grow vigorously into a shrubby plants about 3 feet (1 metre) high by 18 inches (500mm) wide.
Digiplexis is best suited to a Mediterranean climate as they’re not super frost hardy, and in Zones 8 or colder they are grown as a long-flowering annual. And treating it as an annual is what you’d also need to do in warmer climates as Digiplexis requires a chilling period to initiate flowering – 4-6 weeks of temperatures at least down to 38-45ºF (4-7ºC), meaning that although it will happily continue to grow, it won’t repeat flower the following year in warmer areas. Having Isoplexis, a shrub from the Canary Islands as a one of the parents, probably also means it won’t be too happy in high humidity.
But those gorgeous flowers, and blooms from mid spring until early autumn are very good reasons to give it a go. As apparently most of the USA and Europe’s gardeners have done in summer 2015, with suppliers running out of stock of all the Illumination series of Digiplexis* some time ago. As this plant is sterile and can be grown quickly from tissue culture, let’s hope we see its availability spread around the world too. (Note: Digiplexis is available in South Africa but not yet in Australia or New Zealand)
* So far, the Digiplexis Illumination series includes Flame, Pink, Raspberry and Apricot.