Text (except where indicated) and photos ©Nancy J. Ondra
A few posts ago, I mentioned seeing a fantastic new plant – Diervilla sessilifolia Cool SplashTM (‘LDPC Podaras’) PPAF – at the Philadelphia Flower Show. Through the miracle that is the Web, an old friend found his way here to Hayefield, and it turns out he was responsible for actually getting the plants to the show, on behalf of another friend. So now, thanks to fellow variegated-plant fanatic Ron Rabideau of Rare Find Nursery and the plant’s breeder, Peter Podaras, I can now share some of the history of Cool Splash.
According to the background information, “The origin of Diervilla sessilifolia Cool SplashTM is a very interesting story rooted in the beginnings of the national not-for-profit research organization, Landscape Plant Development Center. Founded in 1990 by Dr. Harold Pellett, the Landscape Plant Development Center has a mission of developing superior, new landscape plants with emphasis on those that are more tolerant of biological and environmental stresses.”
“As a not-for-profit, The Center relies on donations and grants to support its research activities. Even Dr. Pellett donates his time as Executive Director of the Center. So in 2003, when the Center hired landscape plant expert and breeder Peter Podaras, it was a sure sign the Center was dedicating itself to expanding its breeding activities. A Cornell Horticulture Department alumnus, Peter helped to establish a cooperative effort between the Landscape Plant Development Center and Cornell University.”
“Peter received his M.S. from the department of Horticulture at Cornell University in Ithaca, NY and then had the fortunate opportunity to work as an intern with Dr. Tom Ranney at NC State in their successful ornamental plant-breeding program. Much of Peter’s earliest work was conducted in the field using the plantings at The Cornell Plantations but then progressed to year-round efforts in the greenhouse.”
“Of all the dozens of plant groups he was asked to work on, diervilla, Peter admits, was his least favorite. Diervilla sessilifolia is a low-growing, suckering shrub native to the south-central US excluding Florida and South Carolina. It is very adaptable to a wide variety of conditions and will even prosper in very cold windy sites. Although Southern Bush Honeysuckle has many desirable attributes, there seemed to be too little genetic diversity in the genus to be able to breed and select superior forms. In fact to Peter, it even seemed a bit weedy and large when grown in full sun. Peter figured that if he tried long and hard enough, he could put the diervilla project behind him and move on to more promising projects. However, in order to do so, he really had to give this genus a serious effort.”
“In the early spring of 2004 Peter started sowing thousands of seedlings of Diervilla sessilifolia in large flats that took up close to 300 square feet of greenhouse space. After seedlings began to germinate, every flat was systematically examined to find any abnormal looking seedlings that might be useful for future breeding. When less than an inch tall all ‘normal’ seedlings were plucked out and discarded. This process took most of the day and was conducted daily, lest any interesting seedling be overtaken by any normal individuals. For about four months, seeds continued to germinate and some interesting seedlings were saved. After seven months, most of the flats were empty. That was when one very unique seedling was noticed.”
“This seedling was only an inch high but had a single leaf with a slight white margin on one side. Knowing that the dormant bud in the leaf axil might have some potential to produce a variegated chimera, the plant was saved and grown to a larger size. The rest of the leaves that grew from that point on were green. When the plant was larger and growing strongly, it was cut back to coax the dormant buds near that first leaf to grow new shoots. One shoot developed green and the other developed into a shoot with a perfect marginal white variegation. The shoot with the variegation was propagated and gave rise to what is now Cool SplashTM.”
As I mentioned in my last post, the straight species of southern bush honeysuckle grows about 3 feet tall for me here in southeastern Pennsylvania, and apparently Cool Splash too is in the 3- to 4-foot-tall range, with a reported hardiness range of Zones 4 to 8. It shares the small yellow flowers and summer bloom period of the species, but the foliage is so dramatically variegated that (to my mind, at least) the flowering display is hardly important. The info supplied to me indicates that Cool Splash can grow in sun or partial shade, so it sounds to me like it will be as tough and adaptable as the species.
The release also mentions that “Deer don’t find diervilla very tasty and generally they leave it alone.” Well, we all know that deer don’t read press releases, so we might be excused for being a little skeptical about that. I can say, however, that the deer that wander around here have left my southern bush honeysuckle plants alone while browsing on trees and shrubs right next to them, so I for one am inclined to believe that they might ignore Cool Splash as well. For more information about Cool SplashTM or the Landscape Plant Development Center, please contact: Landscape Plant Development Center P.O. Box 444 Mound, MN 55364; (952) 443-1505 (telephone); (952) 474-9440 (fax).