The Journey of Physocarpus - Eastern Ninebark

Physocarpus opulifolius, the Eastern ninebark, is a tough, hardy, adaptable native shrub that can be found growing here in Michigan along the shores of Lake Michigan and Lake Superior. According to the USDA, the species can be found growing as far south as Florida and as far west as Colorado. With the exception of native restoration projects, you don't normally see this species cultivated - unless it is a cultivar with colorful leaves.

The native range of Physocarpus opulifolius, Eastern ninebark
If you were to look back about twenty five years into the past, you'd basically have two cultivars of Physocarpus to choose from, both with gold foliage. One was a Dutch selection called 'Dart's Gold', and the other an American selection named 'Nugget'. We have trialed both of these plants in our test garden and while the two plants are quite similar, I have to give the nod to 'Dart's Gold' as the better plant. 'Dart's Gold' has a nicer habit, holds its yellow foliage longer into the summer and has shown less susceptibility to powdery mildew. Powdery mildew can be problematic with Physocarpus, and our test garden has some ideal locations for encouraging mildew and so is a great place to evaluate resistance.

Physocarpus 'Dart's Gold'

Physocarpus 'Nugget'
Roughly twenty years ago, something quite unexpected happened. In Germany, a seedling grower discovered a single Physocarpus plant in his field that had dark burgundy leaves. How or why this happened, nobody knows. The grower shared it with his friend Holger Hachmann, a well-known Rhododendron and Ilex (holly) breeder. Holger put it into his display garden where Gunter Kordes, a German shrub grower, noticed it and recognized its commercial value. Together they introduced it as 'Diabolo', (the German name for child's spinning top). When it was introduced in the United States by Monrovia, the name was changed to Diablo® (cv. ‘Monlo’ PP 11,211) giving a nod to its unique dark red foliage. This was a seminal moment in the world of ornamental Physocarpus

Physocarpus 'Diabolo'
Diablo was an instant hit in the gardening world with thousands, if not millions, of plants
sold worldwide. But the story does not end there. Diablo had a few shortcomings that needed to be addressed. First off, it's a very large shrub, reaching 12-15' in height, making it much too large for most residential gardens. It's also susceptible to powdery mildew which turns its dark red foliage into an eyesore. And lastly, it has a tendency to revert, sending up green shoots every now and then. Recognizing both its potential and shortcomings, I crossed this dark leafed plant with a dwarf, green cultivar called 'Nana'. By using the green-leafed 'Nana' as the mother and the red-leafed Diablo as the father, I knew immediately that any burgundy seedlings were true crosses between the two plants. The result was the introduction of Summer Wine® Physocarpus (cv. 'Seward' pp#14821). This selection solved this mildew issue. It reduced the size of the plant down to a manageable six to eight feet, and the reversion issue disappeared. In addition, Summer Wine was blessed with a graceful, cascading habit and abundant flowers produced up and down the the length of the stems. But the story continues.   
Summer Wine® physocarpus in a decorative container

Around the same time, our friends at Minier Nursery in France planted Diablo in their trial garden next to 'Dart's Gold'. Within a few years, they discovered a chance seedling that was obviously a cross between the two plants. They shared it with us and we introduced it as Coppertina® because of its beautiful, orange-copper foliage.  

Copperina® ninebark

Soon after, others got into the Physocarpus breeding game and scads of Diablo crosses were rushed to market in the US and overseas. Burgundy Star, Center Glow, Angel, Ruby Spice, Red Baron, Royalty, Mahogany Magic, Obsidian, Amber, Black Jack, Barberone, Little Devil, Sweet Cherry Tea, and Raspberry Lemonade are just a few of the cultivars that flooded the market.  Meanwhile, at Spring Meadow, we continued to breed Physocarpus, but for a number of years we introduced nothing. Every time we thought we had unique new selection, powdery mildew reared its ugly head. While the plants looked great at first, after three or four years of trialing, mildew became an issue. What else could we do but destroy the plants and continue to breed? We trialed many of the selections listed above, but they too had mildew issues. To make matters worse, we started getting reports that people were having mildew issues with Coppertina®. 
Finally, with time and persistence, we hit the mark. We developed a dark-leafed, dwarf variety with a high level of mildew resistance and introduced it as Tiny Wine® (Physocarpus 'SMPOTW' pp#26,749). This petite ninebark has burgundy foliage, richly colored pink flower buds and attractive red fall color.     

Tiny Wine® ninebark

Tiny Wine® ninebark fall color

Through the same breeding line we were able to come up with a gold version of Tiny Wine® that was naturally named Tiny Wine® Gold (Physocarpus 'SMPOTWG' pp#28,857). What really impressed us about this plant was how well it looked in a container. Most Physocarpus selections do not flower well as a young plant, so you don't get many flowers on a one or three gallon plant. Tiny Wine® Gold is unique in that it flowers like crazy, even as a young plant. 

Field trials of Tiny Wine® Gold inspected by Dale Deppe.

Exceptionally floriferous as a young plant, Tiny Wine® Gold makes a great container plant.

With time, we were also able to come up with a replacement for Coppertina® which we named Ginger Wine™ (Physocarpus 'SMNPOBLR ppaf). It had the mildew resistance that we were looking for and the brightest orange foliage we had ever seen. Add to that orange-red seed capsules and we had a real beauty. 

Ginger Wine® is an improved, orange, mildew resistant variety that replaces Coppertina®
Ginger Wine™ remained mildew-free in our trials

Seed capsule display on Ginger Wine™

Over the years we came up with a number of very beautiful selections with dark black foliage. Some of the breeders we work with also brought us remarkable plants with dark black foliage. We came very close to introducing a few of these black-leafed selections, only to pull them back at the last minute due to mildew issues. It seemed like the darker the foliage, the greater the susceptibility to mildew. This could be the case, or it could be that the back foliage make it easier to see the light grey mildew infections. Regardless, the hunt for a good black-leafed ninebark was a lot like searching for a unicorn. Pretty much impossible!  

Evaluating for mildew susceptibility and resistance is essential.  

After growing out and destroying hundreds of potential black-leafed plants, we had pretty much given up on the black unicorn. But finally we found it. Summer Wine® Black will be introduced to the trade this spring. It is a compact plant with attractive, dark black, glossy foliage. It's not a strong blooming plant, and so it will be grown primarily for its clean, dark, glossy foliage and compact habit. But finally we had a truly black leafed selection worthy of introduction.     

Field trials of Summer Wine Black™.

Summer Wine® Black container trials show clean foliage and a well-branched habit.

I find it fascinating to look back on the journey of Physocarpus from native to ornamental. The story starts in the United States and moves to Europe, but returns home again. What were the odds of finding that one naturally occurring, red-leafed seedling in a field in Germany? I think about all the plant breeders that made hundreds of crosses and sowed out thousands upon thousands of seedlings looking for one worthy plant. I think about the years of trials and testing needed to verify a truly dwarf selection and the time it took to tame the the powdery mildew problem. And now the story comes to our present time. We have a range of really good landscape plants with attractive black, orange, red, and yellow foliage. We have useful dwarf selections in burgundy and gold. Colorful and easy to grow, these new ninebark selections are ready to provide food and shelter for songbirds and season-long color for our gardens. It's been a long and arduous journey, but so much has been accomplished in just twenty five years. I doubt the Physocarpus story ends here. New and better plants will be developed. We are still making crosses and evaluating fields of seedlings. What other surprises are hidden in the genes of this native shrub? Only time will tell.     



Russian Hardy

I recently had the opportunity to speak to the Russian Nursery Stock Association at their annual conference in Moscow. This is the second time I have spoken at this conference and the attendees were once again eager to learn about new flowering shrubs that are hardy enough for Russian winters. 

The winters in Moscow are very cold and similar to what we experience in Michigan. It has a continental climate so they get plenty of snow and have unpredictable spring weather. Of all of the plants that I spoke about at the conference, the Invincibelle® line of Hydrangea arborescens drew the most attention. In Russian they have the same issues with Hydrangea macrophylla that we have, losing their flower buds and failing to flower. So having a broad line of winter hardy, reliable blooming hydrangeas was good news to the Russians (as it is for most of us in the US and Canada). 

This last year Proven Winners introduced three new hydrangeas in the Invincibelle® line bringing the total to five unique shrubs with an expanded color range of mauve, green, white, pink and red. The series offers a number of dwarf sized plant sizes starting at two and a half feet tall and a few plants that reach four to five feet in height. Add to that three additional varieties of Hydrangea arborescens, the Incrediball® series and Lime Rickey®, and you have eight hardy hydrangeas that can easily handle the worst Moscow winter. If you live in a climate where Hydrangea macrophylla flowering can be hit or miss, this is welcome news. If you own a garden center and you are tired of dealing with customers complaining about their hydrangeas not flowering, this is great news. Here is a synopsis of the hydrangeas I shared with our Russian cohorts at the APPM conference.

Invincibelle Limetta®

One of my favorites, Invincibelle Limetta® hydrangea has a unique short stature with iridescent green flowers from head-to-toe. It was a standout in our test field garnering attention from everyone including Rosie our nursery dog. It glowed in our trial garden where we planted it as a low border hedge, showing off its design value in the landscape. In full sun, particularly in the South, the flowers will transition to white before aging to dark green.    

Rosie knows how to pick out the best plants

Invincibelle Limetta® as a low border hedge in our trail garden

Excellent flower coverage makes this plant a standout!

Invincibelle Mini Mauvette®

There is a lot to like about Invincibelle Mini Mauvette® hydrangea. The mauve colored flowers are a major breakthrough. The color varies depending upon the age of the bloom. In bud the flowers open a rich purple and lighten as the flowers mature. Eventually, the flowers age to a blue-green dusted with shades of purple and red. The leaves and stems have a very strong substance to them, keeping the plant neat and tidy throughout the summer. Its dwarf, compact habit make it a good companion with Invincibelle® Limetta, Ruby and Wee White.

Invincibelle Mini Mauvette® unique flower color

Strong stem strength makes Invincibelle Mini Mauvette® an excellent garden plant

Blooms age to a blend of green, purple and red

Invincibelle® Ruby

Dr. Tom Ranney knew he had a winner when it first saw Invincibelle® Ruby in bloom in his breeding field. This dwarf, compact selection brings us another color breakthrough in Hydrangea arborescens. Dark burgundy-red buds expand in mid-summer and mature to a rich reddish-pink. The undersides of the petals remain dark while upper side lightens to pink giving the blooms a two-toned contrast. Eventually the flowers lighten to pink and change to green. Invincibelle® Ruby hydrangea has been a standout plant in our test field and our trial gardens. 

Dr. Tom Ranney admiring the original Invincibelle® Ruby 

The unique flower color is a first.

Invincibelle® Ruby in our trail garden in Michigan.

Invincibelle® Spirit II

Even though Invincibelle® Spirit was a breakthrough plant, being the first ever pink Annabelle-type hydrangea, it did have its problems. It did not look good in a container at retail and it took a few years in the garden to build up a body. Invincibelle® Spirit II has solved these issues and gives us even richer flower color. The foliage is also darker and more substantial and the blooms age to a pleasing, rich green. This is a big, bold plant that makes a statement in the garden. It has been a performer in our test field and in our trial garden. And like the original, which it replaces, $1.00 per plant sold supports breast cancer research.   

Version 2.0 has stronger stems and richer flower color.

Invincibelle® Spirit II - a standout plant in our test field.

Improved flower color with version 2.0.

The aged, green blooms are are another improvment.

Invincibelle Wee White®

Normally, white flowered shrubs don't get people all that excited, but Invincibelle Wee White® breaks all the rules. The smallest of all the plants in the series, this little beauty is a button of blooms. The flowers start out a soft green then change to white, occasionally showing a whisper of pink just to make things interesting. Year after year, this plant shined in our test field and drew lots of attention in our trial garden. Based on our trials and initial sales, you're going to be seeing a lot of this plant in landscapes near you.    

Blooms all the way to the ground.

The smallest of all the Invincibelle® selections.

Invincibelle Wee White® flowers will at times show a touch of pink and green.


While Incrediball® hydrangea is not a new plant, it is new in Russia. Again, despite being white, this plant has defied all sales expectations. The numbers just keep going up and up, year after year. I think that consumers are just getting to know this plant. Skeptical at first, people that have grown Incrediball® hydrangea have come to be true believers. As an example, two years ago I gave a talk at the International Hydrangea Conference on Cape Cod. During the conference there was a thunderstorm. Afterwards, when we visited the garden, a bed containing both Annabelle and Incrediball made everyone at the conference believers, including Dr. Michael Dirr. The Incrediball® hydrangea was unfazed, while Annabelle, planted right next to it, was a twisted wreck.    

Incrediball® continues to grow in popularity. 

An Incrediball® flowering hedge in our trial garden.

Incrediball® Blush

For some people, the bigger the better. And just like Incrediball®, Incrediball® Blush has really big flower blooms. This is a fulled sized plant with large, silver-pink flowers held high on super strong stems. As you can see below, Incrediball® Blush was a stand out plant in our test field. Even after a number of rain storms these plants looked great. The flower buds open a rich pink and then take on its silver-lavender-pink coloration as the blooms mature.  

Incrediball® Blush a standout plant in our test field.

Big silver-pink blooms on super strong stems.

Lime Rickey®

This plant was a late save. Initially we did not put it in the Proven Winners program because we knew we had a green flowered hydrangea coming with Invincibelle Limetta®. But after watching it year after year in our trial garden we had a change of heart. This plant is definitely Proven Winners worthy. It shines like a beacon in the garden, drawing your eye and your admiration. The contrast between the bright lime-green flowers and dark green leaves adds to it uniqueness and charm.  It stands up to rain storms never missing a beat. The flower heads are not supper big, but that's OK, it just adds to its grace and beauty.  

Lime Rickey® looking good in our trial garden.

A range of green colors delight the eye.

Lime Rickey® hydrangea blooms contrasting with dark green leaves.

I had some extra time after the conference in Moscow, so I took a high speed train to Saint Petersburg for some sight seeing. It's a beautiful city filled with fascinating history and awesome architecture. The people were friendly, the food was tasty and I always felt safe. If you ever have the opportunity to go there, I highly recommend it. Here are a few of the sights I saw. Perhaps they might tempt you into taking the trip. Until next time.

Bronze statue of Peter I

                                                                         Kazan Cathedral

Pushkin Catherine Summer Palace

That's me in front of Church of the Savior on Blood

The Hermitage Museum - former Winter Palace

See you in Cincinnati

I love getting out and talking new plants. On August 31st I will be a part of the Cincinnati Zoo and Botanical Garden's Plant Trials Day Symposium. I'm sharing the stage with some pretty great speakers, so it's going to be a great day if you love learning about new plants. Hope to see you there!

Replacing Roses Affected by Rosette Disease

Time after time designers, landscapers, municipalities and homeowners overuse certain plants to the point of making them a monoculture and then an insect or disease comes along and wreaks havoc. We’ve seen it with elm trees, ash trees and now we are seeing it with landscape roses. Rose Rosette Disease (RRD) is now knocking out landscape roses particularly in the South. The virus is spread by a tiny eriophyid mite that has an association with multiflora rose, so the disease is likely to intensify throughout the Midwest in states where multiflora rose has naturalized.  At the moment there is no cure for Rose Rosette Disease, so infected roses need to be destroyed and replaced with something other than roses.

Roses infected with Rosette Disease look like they've been sprayed with herbicide

While almost all roses are susceptible to RRD, a few specific landscape rose varieties have been hit particularly hard because of their popularity with landscapers and their use in larger mass plantings. The popular question now is what shrub should be used to replace these roses? First off, we should not replace these infected roses with just one single species or cultivar lest we tempt fate once again. We should be looking at multiple species and cultivars, particularly those shrubs that offer similar characteristics that made these roses so useful and popular in the first place.   

Conceptually, the type of shrub landscapers and designers are looking is colorful, carefree, is long blooming or has season-long interest, looks good as a mass planting, thrives in full sun and is less than five feet tall. There are a number of shrubs that meet that criteria and here are some of the Proven Winners® shrubs that fit the bill.

Abelia – Full sun
Long blooming shrubs, many with colorful foliage and fragrant flowers.
               Bronze Anniversary™ - 3-4’
               Ruby Anniversary™  - 4-6’
               Sunny Anniversary® - 3-4’
               Pinky Bells® - 3-4’
               Fairy Dance™ - 2-4’

Ruby Anniversary™ Abelia chinensis

Aronia – Chokeberry – Full sun
Low Scape® Series - A tough native with white spring flowers, glossy foliage and exceptional fall color.
                              Low Scape® Hedger - 3-5’
                              Low Scape® Mound - 1-2’

Lo Scape® Mound Aronia in autumn

Azalea – Rebloooming – Full sun to partial shade
Bloom-A-Thon® Series - Compact evergreen shrubs with showy flowers that appear in the spring and fall.
Bloom-A-Thon® Hot Pink – 3.5-4.5’
Bloom-A-Thon® Lavender – 3.5-4.5’
Bloom-A-Thon® Pink Double – 3.5-435’
Bloom-A-Thon® Red – 3-4’
Bloom-A-Thon® White - 2.5-3’

Bloom-A-Thon® Double Pink Azalea

Berberis – Barberry – Full sun
               Sunjoy® Series - Tough, easy to growing shrubs with colorful foliage. 
          Sunjoy® Cinnamon - 4-5’
Sunjoy® Citrus - 2-3’
Sunjoy® Gold Pillar - 3-4’
Sunjoy® Syrah - 4-5’
Sunjoy® Tangelo - 3-4’

Sunjoy® Series of Barberry

Buddleia – Dwarf Butterfly Bush - Full Sun
Continuous flowering, low growing shrubs with colorful, fragrant blooms.
          Lo & Behold® Series – Dwarf, sterile shrubs that come in a wide range of colors.
Lo & Behold® Blue Chip - 2-2.5’
Lo & Behold® Blue Chip Jr. - 1.5-2.5’
Lo & Behold® Ice Chip - 1.5-2’
Lo & Behold® Lilac Chip - 1.5-2’
Lo & Behold® Pink Micro Chip - 1.5-2’
Lo & Behold® Purple Haze - 2-3’

Lo & Behold® Pink Micro Chip

Miss Series – Semi-dwarf shrubs with vibrant colored, fragrant flowers.
               'Miss Molly' - 4-5’
               'Miss Pearl' - 4-5’
               'Miss Ruby' - 4-5’
               'Miss Violet' - 4-5’

Miss Violet Butterfly Bush

Pugster™ Series - Dwarf shrubs with large flowers with a wide range of colors.
                    Pugster™ Blue - 2’
Pugster™ Periwinkle - 2’
Pugster™ Pink - 2’
Pugster™ White - 2’

Pugster Blue™ Butterfly Bush

Ceanothus hybrids – New Jersey Tea - Full sun
               Marie Series™ - Drought tolerant shrubs that thrive in poor soils.
                              Marie Bleu™ - 2-3’
                              Marie Gold® - 2-2.5’
                              Marie Rose™ - 2-4’                  

Marie Blue™ Ceanothus
Clethra alnifolia – Summersweet - Full sun to partial shade
Easy to grow native shrubs with later summer, fragrant flowers and yellow fall foliage
               Sugartina® Crystalina - 2.5-3’ 
               Vanilla Spice® - 3-5’

Sugertina® Crystalina Summersweet

Deutzia gracilis – Slender Deutzia - Full sun to partial shade
Yuki® Series – Tough, ground covering shrubs with abundant spring flowers and burgundy fall color.
                              Yuki® cherry Blossom - 1-2
                              Yuki® Snowflake - 1-2’

Yuki Cherry Blossom™ Deutzia

Diervilla – Bush Honeysuckle - Full sun to partial shade
          Kodiak® Series – Tough, native shrubs with colorful spring and autumn foliage.
Kodiak® Black - 3-4’
Kodiak® Orange - 3-4’
Kodiak® Red - 3-4’

Kodiak® Orange Diervilla

Hibiscus syriacus – Dwarf Rose of Sharon or Althea - Full sun
               Lil’ Kim™ Series – Dwarf series from Korea with colorful, long blooming flowers.
                    Lil’ Kim™ White - 3-4’
Lil’ Kim™ Red - 3-4’
Lil’ Kim™ Violet - 3-4’
               PollyPetite™ - 3-4’,  A sterile, dwarf hybrid with a large clear lavender blooms

Pollypetite™ Hibiscus

Hydrangea arborescens – Smooth Hydrangea - Full sun
               Lime Rickey® -  4-5’, Attractive green flowers
               Incrediball® -   4-5’, Large flowers emerge green, turn white and age to green.
               Incrediball® Blush -   4-5’, Large lavender-pink flowers on strong stems.
               Invincibelle® Series – Compact/dwarfs with strong stems, wide range of colors.
                    Invincibelle® Limetta™ - 2.5-3’
Invincibelle® Ruby - 2-3’
Invincibelle® Wee White™ - 1-2.5’

Invincibelle® Spirit II (Two) in our trial fields

Hydrangea macrophylla – Reblooming Bigleaf Hydrangea - Full sun to partial shade
               Let’s Dance® reblooming series – Reliable, long blooming, rich flower colors.
          Let’s Dance® Big Easy® - 2-3’
          Let’s Dance® Blue Jangles® - 3-4’
Let’s Dance® Diva! - 3-4’
Let’s Dance® Rave™ - 2-3’
Let’s Dance® Rhythmic Blue™ 2-3’

Let's Dance® Big Easy™ Hydrangea

Hydrangea paniculata – Dwarf Panicle Hydrangea - Full Sun
               Bobo® - 2.5-3’
               Little Lime® - 3-5’
               Little Quick Fire® - 3-5’

Bobo® Hydrangea

Hydrangea serrata – Serrated Hydrangea - Full sun to partial shade
             Tuff Stuff™ Series – Selected for hardiness and reliable blooming.
Tiny Tuff Stuff™ - 1.5-2’
Tuff Stuff™ - 2-3’
Tuff Stuff™ Red - 2-3’

Tiny Tuff Stuff™ Hydrangea

Hypericum –St. Johnswart - Full Sun
               Sunny Boulevard® - 2-3’, Tough, drought tolerant and long blooming

Sunny Boulevard® Hypericum

 Itea virginica – Dwarf Sweetspire - Full sun to partial shade
Little Henry® - 2-3’, A dwarf selection with early summer blooms and excellent orange-red fall color.

Little Henry® Itea

Lagerstroemia – Dwarf Crapemyrtle - Full sun
               Infinitini® Series – Dwarf compact shrubs, that flower even if they die back.
Infinitini® Brite Pink – 2-4’
Infinitini® Magenta – 2-4’
Infinitini® Orchid – 2-4’
Infinitini® Watermelon – 2-4’

Infinitini® Magenta

Ligustrum - Privet - Full sun to partial shade
               Golden Ticket® - 4-6’, A non-invasive, non-burning, bright yellow-green foliage.

Loropetalum – Dwarf Chinese Fringe Flower - Full sun to partial shade
Jazz Hands® Series – Selected for healthy growth and attractive flowers and foliage.
Jazz Hands® Bold – 5-6’
Jazz Hands® Dwarf Pink – 1-3’
Jazz Hands® Dwarf White – 1-3’
Jazz Hands® Mini – 1’
Jazz Hands® Variegated – 4-6’

Jazz Hands® Bold and Mini

Physocarpus – Dwarf Ninebark - Full sun
Dwarf selections with colorful foliage and a high level of mildew resistance             
Festivus Gold® - 3-4’
Tiny Wine® - 3-5’
Tiny Wine® Gold – 3-5’   

Potentilla – Bush Cinquefoil - Full sun
Happy Face® Series - Tough, free flowering native shrubs with a range of colors.  
Happy Face® Pink Paradise – 2-3’
          Happy Face® Yellow – 2-3’

Happy Face®  Yellow Potentilla

Spiraea - Spirea - Full sun
Double Play® Series – Attractive spring foliage color and superior flowering.
                    Double Play® Artisan® - 2-2.5’
Double Play® Big Bang™ - 2-3’
Double Play® Blue Kazoo® - 2-3’
Double Play® Candy Corn™  - 1.5-2’
Double Play® Gold – 1.5-2’
          Double Play® Painted Lady™ - 2-3’
          Double Play® Pink – 2-2.5’
                    Double Play® Red™ - 2-3’

Double Play® Blue Kazoo® Spiraea

Weigela - Weigela - Full sun
Sonic Bloom® Series – Continuous flowering in a range of flower colors.
Sonic Bloom® Pink – 4-5’
Sonic Bloom® Red – 4-5-

Wine Series™ – Early summer flowers and attractive burgundy foliage
Fine Wine® - 2-3’
Spilled Wine® - 2-3’

Wine & Roses® - 4-5’

Sonic Bloom® Red Weigela