Making a Splash

Diervilla sessilifolia Cool Splash ('LPDC Podaras') with Sanguisorba menziesii 'Dali Marble'

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.”

Diervilla sessilifolia Cool Splash ('LPDC Podaras') with Calamintha 'White Cloud'

“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.”

Diervilla sessilifolia Cool Splash ('LPDC Podaras')

“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.

Diervilla sessilifolia Cool Splash ('LPDC Podaras') with Browallia americana

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).

14 responses to this post.

  1. Posted by ourfriendben on March 17, 2008 at 9:58 am

    Wow, Nan, this *is* a stunner! And I like the way the straight species looks, too. Thanks for sharing the new photos!

    I’m quite sure it will look even better in my garden, Elly. And if it grows half as well as the species does for me, it’ll be awesome.
    -Nan

  2. Isn’t it interesting to find the history of a new plant! Thanks for this and I will be looking to add both species and cultivar to my garden! So many plants, so little space!

    I’m glad you like it too, Layanee. Just when I start getting a little jaded by new introductions that don’t look all that new, something really different like this comes along.
    -Nan

  3. I find that learning how the plants are made is as interesting as the plants themselves. Thanks for the information! It looks like a really neat plant!

    I agree, Dave. I’d occasionally heard about the Landscape Plant Development Center but didn’t know what it was all about. It’s been exciting learning about the great plants they’re developing!
    -Nan

  4. I’m a bit leery of the bush honeysuckle, we have a horrible weedy tree type honeysuckle that is a bane, seedlings everwhere due to the birds eating the berries, but it may not be the same, growing to at least fifteen feet. BUT hearing the story of how a selection is made with the promise of something special for the garden was fascinating. The new cultivar is attractive and being the great designer your are you can find a pleasing combination for it in the garden if anyone can.
    Frances at Faire Garden

    I totally understand your concern, Frances, because we have invasive shrub honeysuckles (Lonicera spp.) up here too. Diervilla is in the same family, but D. sessilifolia is native to parts of Tennessee, and it has tiny seeds rather than bird-attracting berries. It spreads gently (in my experience) by suckers, but I don’t think it’s considered weedy anywhere.

    As far as companions for Cool Splash, I hadn’t thought that far. I can see it paired with Persicaria polymorpha, maybe, or something else that’s either tall with white flowers or short with solid green leaves. Hmmm…
    -Nan

  5. Very interesting to learn about the history of this plant–cool post. :)

    Thanks, Brianna!
    -Nan

  6. It will be fun to see if you or I get it first ;)
    You now that we have the same taste.
    I dont think it will relace in Sweden first,so I think you get it first…hm.
    Ken

    Hi Ken! No, I’m not at all surprised that it appeals to you too! I think we’ll both have a bit of a wait, but I’m sure it will be worth it.
    -Nan

  7. Very pretty. I love variagation. Your blog is very nice.

    Welcome, Linda! I’m glad you found your way here; it’s always good to meet another variegated-plant fan.
    -Nan

  8. Yes! Me too. Lovely. Thanks for telling us the story. The process is amazing.
    Carol
    terranovadesign.blogspot.com

    Doesn’t it make you sad to think of all those other seedlings being destroyed, though? Peter explained to me why that’s often so important: If a breeder has put several years of work into making crosses, they can’t take the chance of someone else getting hold of one of the seedlings and cashing in on the work. But oh, think of all those lovely-though-maybe-not-perfect plants being deemed unworthy and meeting an untimely end. I not sure wouldn’t have the necessary discipline to do that. But maybe it’s easier when you’re surrounded by a bounty of even better plants!
    -Nan

  9. Nan, first of all, thanks for the great story. I never realized how much work went into seeding and selecting for new plant material. Secondly, I’m thrilled to read that this plant would grow well in zones 4 – 8. I will be on the look out for it next year for sure!

    I’m glad you too found it of interest, Melanie! With variegates, especially, I often think of them just appearing in the wild or in a garden and then being spotted by some eagle-eyed gardener or nursery owner. I guess it’s somewhat the same in this case – but when you’re starting with many thousands of seedlings, the odds of finding something special are much better.
    -Nan

  10. nan – completely unrelated to this post – CONGRATS ON WINNING THE AWARD FOR YOUR BOOK! I didnt even know you had a book! I’m going to pick it up ASAP. i love it when my garden blogging friends get famous!

    Thanks so much, Gina! I’m pretty excited too!
    -Nan

  11. Congratulations on your award! Your perspective on plants is great, I’m glad it’s being rewarded. :)

    Thank you, Dave. In this case, I think it’s the perspective of the photographer, Rob Cardillo, that really carries the concept!
    -Nan

  12. I love the variegated southern bush honeysuckle and am going to try to find a place for it in my garden.

    Oh, yes! That is wonderful news about your award!

    Gail

    Thanks, Gail! While we’re waiting for Cool Splash, you might consider trying the straight species. I think it’s a good plant even without the variegation.
    -Nan

  13. I can see why you like it with those great variegated leaves. Interesting reading the history. I’ll look forward to seeing it in your garden one of these days Nan.
    Congratulations on your book award!!

    Thanks so much, Kerri! I too look forward to seeing Cool Splash in my garden.
    -Nan

  14. I thank you for the information about this new and spectacular plant. I work for The Conard-Pyle Company in Jennersville,PA and thought I would let you know that we are growing over 2000 of these for Spring 2009, so every nursery in the mid-Atlantic and Northeastern US will have an opportunity to sell these to their customers.

    Thanks again! Neil

    Thank *you* for the news, Neil. I know a bunch of us are dying to get our hands on ‘Cool Splash’!
    -Nan

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