‘Summer Sun’ coneflower

For years we were happy to grow coneflowers in every shade of well, umm, purple. Echinacea purpurea is still one of my favourite coneflowers because it seems to harmonize with so many other perennials, from pink phlox to golden rudbeckias. And they sure look good with ornamental grasses, too.

But recent plant breeding has introduced a rainbow of colours to the coneflower palette, and the orangey-red ‘Summer Sun’ featured in this season’s INSIDER REPORT is one of this new breed.

A while ago, in an effort to introduce winter hardiness into the purple coneflower strain, plant breeders started crossing them with yellow-flowering ones, which were better at tolerating cold and moist winter conditions. What surprised breeders was that the new generation of coneflowers blooms in a wide range of warm colours, from soft lemony yellows and dusty pinks to bright oranges and scorching reds. It’s not exactly like setting out to invent radar and ending up with the microwave oven, but the coneflower breeding program certainly has spoiled gardeners with a kaleidoscope of stunning new colours.

And speaking of colour, if you’ve picked up one of these new beauties recently, you might have noticed that the flower colour on the tag might not match the actual colour of the flower you just planted in your garden. To help explain this puzzle, I spoke with Susan Martin of Walters Gardens (they’re the folks who brought us ‘Summer Sun’ from Holland where it was bred).

“One important thing to know about the orange echinaceas”, she says, “is that direct UV light is required to properly develop the layers of yellow and pink that combine to make up the orange flower colour. When grown in the artificial environment of greenhouses, such factors as UV inhibitors in greenhouse plastic as well as the quality of light, temperature and day length can influence petal colour, bringing out either more yellow or more pink.” But Susan assures us that once planted outside under direct sunlight, the flower colours should develop as shown on the tag.

Because these plants are so new, growers are still learning about their growth habits. Currently, there’s a discussion about the best way to overwinter them. Many of the new varieties are crosses between purple coneflowers (Echinacea purpurea), which develop long taproots that can store enough food to get them through the winter, and yellow coneflowers, (E. paradoxa), which have a fibrous root system. This characteristic of the yellow coneflower strain means that these new yellow-orange varieties need to develop a good-sized crown in late fall to get them through their first winter. So, some professional growers are advising gardeners to cut off the flowers of first-year plants to redirect plant energies into producing a substantial mound. In fact, I tried this last year with a new variety called Sundown, and it’s the largest clump of coneflowers in my garden.

But in the display gardens at Walters Gardens, Susan says they have no problem overwintering coneflowers – whether the flowers have been cut off or not. (In fact, their biggest problem is keeping away the rabbits!) 

“Probably one of the biggest factors in overwintering success,” she adds, “is having healthy plants that are sited properly going into winter. Echinaceas prefer light, loamy soil enriched with a little bit of humus and they must have very good drainage. These plants do not like it wet in winter, so you wouldn’t want to plant them where you pile snow for the winter if your climate tends to have periodic freeze/thaw cycles.”

I don’t know about you, but to be safe, I’m planning to follow the advice of all the experts and give these new coneflowers the right growing conditions – and hedge my bets by cutting off the flowers of first-year plants!