How one nurseryman selects the best new varieties
by MAURICE HORN photography by JANET LOUGHREY
THERE IS A SAYING THAT PERFORMERS must leave their homes to gain recognition. The same is true of the large-flowered hybrid penstemons. Seeds of the numerous North American species that make up these hybrids had to cross the Atlantic and find their way into the hands of the great 19th- and 20th-century European hybridizers, where they became magnificent garden plants. Hundreds of cultivars that had been bred are now lost, but the abiding presence of this group of penstemons is a testament to their usefulness and long-term beauty. They bloom from summer to the first hard frost in our gardens in Scappoose, Oregon.
A NEED FOR MORE
On a recent trip to England, I was surprised at how many new penstemon hybrid cultivars I found at each nursery I visited. It had only been six years since my last visit, but I found so many unfamiliar names that I felt like Rip Van Winkle in penstemonland. The great number of new cultivars is evidence of the ease with which these large-flowered hybrids cross with one another. They lend themselves readily to the production of plants for a gardening public that is always hungry for something new.
When I returned to the States, I did wonder if there was really a need for more penstemon hybrids. I considered this because we have a substantial collection of large-flowered hybrid penstemons here at Joy Creek Nursery (www.joycreek.com), and it is not uncommon to find seedlings in the garden. Although most of these seedlings are destined for the compost pile, in 2001 we had found a seedling with an indefinable quality that made us hesitate to remove it. We began a year-long evaluation to determine whether we should pursue developing this seedling or let it find its way to the compost with the others.
A NURSERYMAN SELECTS
Flower color is the most obvious way to evaluate a plant. The colors of the large-flowered penstemons range widely from white to dark purple. In between, there are pink, scarlet, red, violet, purple, blue, and many other intermediate colors. Our new seedling was decidedly burgundy, not far from the color of Penstemon ‘Wine Kissed’. On the basis of that similarity alone, we might have eliminated the plant.
Flower shape and size are other obvious parameters. Penstemons have tubular flowers. In profile, their tubes can be long and narrow, foreshortened and broad, or somewhere in between. The flowers of P. ‘Raven’ have long, narrow tubes; those of ‘Bev Jensen’ have broad, foreshortened ones. Our seedling had flowers very similar to the latter.
Face-forward, the lip of the tube is divided into five lobes: two on top, three on the bottom. Typically, the lip recurves, revealing the interior of the throat. The width of the flower can vary greatly. The classic ‘Blue Midnight’ (syn. ‘Midnight Blue’) is only three-quarters of an inch wide; ‘Raspberry Flair’ is two inches. Our seedling’s flower was over two inches wide, making it the largest in our collection. Blossom size alone, however, does not make a penstemon great.
The throats of penstemons are very dramatic. Most have guidelines, just like lines on a runway, directing pollinators to the nectaries deep within their tubes. Some guidelines are dark and some are faint. From time to time, flowers have no guidelines whatsoever, as in ‘Violet Kissed’. Penstemon flowers are such inviting, waterproof shelters that pollinators find the nectaries even when the guidelines are absent. It is not uncommon to find bumblebees and other visitors asleep within the flowers early in the morning. Our seedling had very pronounced burgundy lines, much like ‘Raspberry Flair’.
After a year of evaluation, we still couldn’t find the concrete reason we found the seedling so interesting in the first place, despite the impressive size of the flowers. It was slated for the compost pile.
A TWIST OF FATE
Clemency arrived at the hands of our propagator. Because of its proximity to other penstemons, she mistakenly took cuttings of the seedling while it was out of bloom. She labeled it with the name of its neighbor, and the following year it was replanted in the garden under that name. When it bloomed, we realized the mistake—and we were relieved to have a chance for another look.
This time, we paid closer attention to other features, first examining the foliage. For the most part, the large-flowered hybrid penstemons have stemless, slender, willowlike leaves. The base of a leaf can be very narrow or quite broad, and leaf color can vary from apple green to dark green (see the photograph of ‘Enor’). Light serration occurs along their margins, but the serration is not regular or consistent. Occasionally, variegation occurs, but it also is irregular, as in our selection ‘Wisley Cream Sport’. The foliage of our seedling was apple green and had the broadest leaves we had ever recorded, more than an inch-and-a-half wide.
We also looked at the height of the plant. When in full bloom, most large-flowered penstemons are between two and three feet in height. ‘Cherry Glow’ reaches a towering four-and-a-quarter feet. Our seedling was compact, at just a little over two feet.
In some cultivars the stems are dark burgundy or red. ‘Rich Ruby’ and ‘Joy’ have particularly attractive stems that complement their red flowers. Our seedling had purple streaking at the tip of its stems.
Finally, we looked at the way the flowers were held on the flowering stem. Often, flowers are held in an airy, one-sided arrangement. This can be tighter or looser depending on the length of the flowering stem. When we compared cut stems of dozens of penstemon hybrids, the beauty of the plant was revealed. Our seedling held its wide flowers in a dense, triangular arrangement, like a ready-to-pick bouquet. This was the winning trait that we had not been able to verbalize when we first saw the plant.
With so many factors in its favor—the flower and foliage size, the compactness, the way the flowers are held, the sheer luck by which it had survived—we decided to grant it a name.
THE NAME GAME
Fortunately, when it had accidentally been replanted, it had been placed between ‘Raspberry Flair’ and ‘Wine Kissed’. When the entire bed was in full bloom, its resemblance to both plants was uncanny. It had the guidelines and flower size of ‘Raspberry Flair’ and the lip coloring and leaf size of ‘Wine Kissed’. In many ways, we felt like we had returned a child to its parents.
And so we named it ‘Raspberry Wine’, wedding the names of the parents together. It has now joined its relatives in the stock field and we are anxious to see how this new garden performer does upon the garden stage. H
For sources of plants featured in this article, tum to page 72.
penstemon care and maintenance
The large-flowered penstemon hybrids are generally hardy from USDA Zones 7 to 10. Although they thrive in our Pacific maritime climate, they dislike our clay soil. We have learned to break up soil by using a combination of organic compost and 1/4 to 1/10-inch gravel (essentially, washed crushed basalt of such diameters). A mix of two to three inches of both the compost and the gravel double-dug or rototilled into the bed keeps their roots from rotting in our wet winters. We also find a two-inch topdressing of the same gravel helps to wick standing water away from the root crown.
The large-flowered penstemons are evergreen shrublets. We wait until March, when we are past the fear of deep frosts, before we cut back the previous year’s flowering stems. This renews the penstemons and makes the plants look tidy for the coming season. Flowering stems will appear throughout the growing season, but removing spent stems during the summer promotes additional blooming into the fall. Remember, always cut above an active point of growth.—M.H.