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Graham Rice's New Plants Blog

Graham Rice Garden writer and plantsman Northamptonshire and Pennsylvania

Editor-in-Chief of the RHS Encyclopedia of Perennials; writer for a wide range of newspapers and magazines including The Garden and The Plantsman; member of the RHS Herbaceous Plant Committee and Floral Trials Committee; author of many books on plants and gardens.

  • Date Joined: 18 Oct 2006

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Digitalis 'Illumination': New from Thompson & Morgan

Posted by Graham Rice on 11 Jan 2012 at 11:28 AM

Digitalis 'Illumination - a new hybrid foxglove. ©Thompson & MorganWe’ve seen some fine new foxgloves in the last year or two but this one is even more special as it brings together two species into a dramatic perennial that’s never been available before.

Digitalis ‘Illumination’ combines the familiar purple colouring of our native foxglove with the rich orange colouring of Isoplexis canariensis, from the Canary Isles. The result is a plant reaching about 2-3ft/60-90cm in height, with spikes of flowers over a very long period. The flowers are sterile, so they just keep on coming.

Shimmering purple, with faint honeyed streaks on the outside, inside the throats are almost white shading to honey orange at the edges. The throats are sometimes noticeably spotted and sometimes not, depending on temperature and light intensity.

This is another plant created by Charles Valin, plant breeder at Thompson & Morgan. He told me about it: ‘I started in 2006,’ he said. “I had a feeling that although Ispolexis was classified as separate from Digitalis, they are so similar that Isoplexis should probably be called Digitalis. I kind of wanted to prove botanists wrong! And I wanted to combine the exotic looking bird pollinated flowers of Isoplexis with the hardiness of Digitalis.

“So in 2006 I crossed various selections of Digitalis purpurea with Isoplexis canariensis. Only certain crosses took, and when they did the seed set was low. We saw the first hybrids in 2007, and they were spectacular. Unfortunately it turned out that the germination of the hybrid seed was very low, so we decided to produce vegetative clones instead, and propagate by tissue culture. We chose one plant with the best habit and strongest colour among about 100 hybrid plants.

“The flower shape of Digitalis ‘Illumination’ retains the nice distinct look of Isoplexis, and because the hybrid is entirely sterile it keeps on flowering and sending new flower spikes all summer long. I have not seen any birds trying to pollinate it yet, but ‘Illumination’ is definitely a bumblebee magnet! The plants survived the 2010 winter in the field and re-shooted in spring from ground level. I expect that in a mild climate the top growth would not die and you would end up with a spectacular shrubby foxglove.”

And yes, Isoplexis canariensis is now treated as a Digitalis.

You can order plants of Digitalis ‘Illumination’ from Thompson & Morgan and look out for them, in bud, in garden centres in May.


Kaveh said:

I NEED one!  I remember back in 2004 when I visited Wisley and saw Digitalis 'Spice Island' there it was hinted that it was a Isoplexis x Digitalis hybrid but I never really found anything confirming that so was suspicious.  There can obviously be no doubt this time. Wonderful plant. I look forward to it being available here in the US.

on 11 Jan 2012 at 06:42 PM

Graham Rice said:

When I hear that 'Illumination' is available in the US I'll post the info here.

on 14 Jan 2012 at 10:34 AM

Ant said:

The power of blogs, I have just ordered some of these from T & M !

on 18 Jan 2012 at 09:45 PM