Plants that Impress

It's the last day of January and there is over a foot of snow on the ground here in Michigan, but spring is almost here. I say this because we turned on the heat in our greenhouses today. We are waking up our plants, so we can start propagating. 

Last year, I didn't post all that much and I'm going to blame it on Covid. The pandemic had such a strong impact on the nursery business and we've been incredibly busy trying to keep up with the demand for plants. My Delta account is full of cancelled tickets, because I did not go to Italy, Germany, Korea or the Netherlands as I had planned. On the positive side I did spend more time in our trial garden, R&D greenhouse and breeding fields evaluating plants. Today I want share with you some of the plants that impressed me the most. Hopefully you'll see something you like, and the spring and summer photos will warm you up until spring arrives for real. Enjoy.

Let's Dance Sky View™ reblooming hydrangea

With each passing year the genetics on our reblooming Hydrangea macrophylla keep getting better and better. Let's Dance Sky View hydrangea is one of the best yet. When we trial reblooming hydrangeas we cut our plants back hard in that fall and once again in the spring. We do this to simulate untimely frosts. We also trial them multiple years outdoors to make sure they'll bloom reliably in our harsh Michigan climate. If they bloom here, the should bloom anywhere. As you can see from the photographs below, Let's Dance Sky View excelled in both our trials, blooming nicely after being cut back as a container or having been frozen back in our field. When treated with aluminum sulfate or grown in acid garden soil, the flowers are an attractive sky blue color.  

Plants on the left were cut in fall and the plants on the right were cut back again in spring

Let's Dance Sky View hydrangeas flowered well after freezing back to the ground in 2020 and 2021.

'Viva Polonia' and Happy Jack® Purple Clematis 

So many consumers are disappointed by clematis and it's not their fault. We set out to change that.  You many not know it, but most clematis varieties on the market are selected for their flower size and how they perform for the grower, while we select ours based on garden performance. 'Viva Polonia' and Happy Jack Purple offer the very best in terms of garden performance. Here you can see how they looked in our trial garden last summer. Simply amazing! 

'Viva Polonia' clematis in our test garden 

Unique reddish-pink, star-like flowers on 'Viva Polonia' clematis

Happy Jack Purple is always looking happy and healthy

Happy Jack Purple climbing on a Quick Fire hydrangea 

Puffer Fish™ Hydrangea paniculata

Puffer Fish™ hydrangea is a new selection developed at North Carolina State University that will be at retail in a year or so.  Think of it as a super-sized Bobo hydrangea. Just like Bobo, it has full, lacy blooms from top to bottom, but the blooms are much bigger. The flowers open pure white and remain white until they transition in fall to a light green. It's also quite distinct in that new flowers continue to produce at the tip of the panicle, making it looks as if the puffer fish flowers are spitting a bit of water. Puffer Fish has been a standout in all our trials.   

Puffer Fish hydrangea in our trail garden
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At full bloom it's hard to see the foliage on Puffer Fish

An easy to identify bloom, Puffer Fish blooms spit a bit of water

Wine & Spirits™ Weigela

We evaluate a lot of Weigela breeding each year and one of plants that shinned was Wine & Spirits™ weigela, a new variety developed by Megan Mathey. What I love about this selection is its fresh greenish-white flowers. I've never seen this color before and it just makes the flowers almost glow against the backdrop of its dark foliage. Growers and retailers will appreciate how well it looks in a container in the spring, and gardeners and landscapers will love how it looks in the landscape. Its unique flower color and overall flower power made it a standout in all of our trials. 

The greenish-white flowers of Wine & Spirits weigela appear to glow 

A standout Weigela in our container trials

With lots of flower power, it lights up a garden even more than Wine & Roses.

Mr. Mustard™ Sorbaria

When we trial a new variety, we compare it to similar plants on the market, and if it's not better we pass on the plant. Mr. Mustard™ Sorbaria sorbifolia was clearly brighter and more compact than 'Sem' and the others. The plant is at its best in spring when it is flushing, showing off its feathered hues of red and yellow. While other selections burn or get ragged by mid-summer, Mr. Mustard Sorbaria passes inspection with its clean green foliage and cherry-red fruit. Be aware this species sends out runners in loamy soils and should only be planted in areas where it is contained. Plant in a isolated bed, or keep it contained by growing it in a decorative container. It's plenty hardy and will overwinter just fine. Its white, conical, summer blooms look a bit like Astilbe and are wonderful for attracting pollinators. This is a tough, hardy plant that performs wonderfully when in the right location.

Mr. Mustard is a colorful container plant 

At its best in spring, Mr. Mustard is colorful and compact

In the summer the foliage turns to green, as opposed to brown like 'Sem'

Sting™ Thuja occidentalis 

I am partial to columnar plants, so it is no wonder that Sting arborvitae captured my heart and imagination. This seedling selection of 'DeGroot Spire' that I sowed out some 15-18 years ago has remained exceedingly slim and attractive. Hardy and heat tolerant, use it as an exclamation point, or go all in and plant it in rows down each side of a road, like the Italians do with their narrow Mediterranean cypress, Cupressus sempervirens. Sting Thuja is a fun tree that is only limited by your imagination.       

Make a statement with Sting arborvitae, the super narrow Thuja occidentalis 

Sting arborvitae in our test garden

That's all for now. Join me soon when we'll take a look at some new and exciting plants specifically for the South. Until then, stay warm. 

Double Play Spirea: More Than Just Pretty Flowers

As a general rule, Spiraea is known as a hardy, adaptable and attractive ornamental shrub. And of the 90 different Spiraea species, few are as colorful and useful as Spiraea japonica. The species is very hardy, adaptable and offers a wide range of flower and foliage colors. Add to this the ability to cross with other species and you have an array of breeding opportunities. With Spiraea, as well as other species, observation and imagination are the first steps in plant breeding, so looking for and noticing things that others may miss, brings new opportunities.

One of our early discoveries was a rich, pink flowered Spiraea fritschiana that we named Pink Parasols® (‘Wilma’). Known for its excellent hardiness and attractive autumn foliage, Spiraea fritschiana is a low mounded, Korean native, with large, attractive blooms that are normally pure white. By pure luck I found this pink flowered anomaly in a batch of seedlings at a local university. The seed source of this plant originated in Korea and I suspect it might have been an accidental hybrid with Spiraea japonica. Pink Parasols is a low mounded plant that is much wider than it is tall, making it an excellent commercial landscape plant. 

Another observation we made early on was that most spirea are sold in the spring, well before the flowers appear. This means that the color, texture and health of the foliage is how most consumers judge the plants they are buying. Further observation revealed that some seedlings had especially good, colorful foliage when leafing out in the spring. Such was the case when we crossed Pink Parasols Spiraea fritschiana with a yellow leafed Spiraea japonica variety and came up with a number of unique, colorful hybrids. After evaluating the top selections, we introduced one and named it Double Play Big Bang® (Spiraea x ‘Tracy’). The spring flush of foliage is a vibrant orange. As the foliage matures it turns bright yellow with contrasting red new growth. The pink flowers are extra-large, getting this trait from Spiraea fritschiana. The plant cultivar was named in honor of my wife Tracy, and has proven itself to be first class garden and landscape plant. Thank goodness for that, because you don’t want to name a bad plant after your wife!

Double Play Big Bang

It is amazing to note the difference in flowering between cultivars as well as seedlings. Some plants only flower in top while others flower from top to bottom. The corymb (bloom) diameter varies greatly between plants. The green-leafed varieties, Double Play Pink (Spiraea j. ‘SMNSJMFP’) and Double Play Artisan® (Spiraea j. ‘Galen’) were all selected for large corymbs and bloom density from top to bottom having pink and purple flowers respectively. Both cultivars are especially attractive in early spring as the new foliage emerges burgundy-red.  

Trialing is one of the most important parts of plant breeding. Double Play Artisan stands out from the crowd

Double Play Red® (Spiraea j. ‘SMNSJMFR’) has beautiful cherry-red spring foliage, but is was primarily selected for its uniquely colored, sangria-red flowers. It is the truest red I have ever seen in a Spirea; better than ‘Dart’s Red’, and far better than ‘Anthony Waterer’.  As the flowers age, the dark red hues do transition to pink, so there are times when the flowers will look more pink than red. Regardless, it is a truly unique and beautiful plant. 

Double Play Red (on the right) is the first true red spirea

Many gold-leaved cultivars being grown in the nursery trade are susceptible to powdery mildew (Podosphaera spiraeae). Double Play® Gold was introduced as a solution to this problem. Double Play Gold (Spiraea j. ‘Yan’) is a compact, dwarf, gold foliaged plant adorned with bright, bubblegum pink flowers. 

Double Play Gold

While most of the plants in the Double Play series were developed by Spring Meadow in our internal breeding program, two varieties were developed by North Carolina State University. A number of years ago, we had funded Dr. Thomas Ranney’s plant breeding team to develop sterile cultivars of potentially invasive plants. 

One of the common methods for sterile varieties is to create a triploid (3x) plant which has three sets of chromosomes instead of the normal two, a diploid (2x). This was the technique used to create seedless watermelons. The process starts by treating young seedlings with colchicine or oryzalin, which doubles the chromosomes, thus creating a tetraploid (4x) plant. The tetraploid plant is then crossed back with a normal diploid plant. The resulting triploid seedlings are often seedless. Double Play Doozie® (Spiraea japonica ‘NCSX2’) is a seedless triploid, as well as a wide cross containing genes of more than one species. One of the added benefits of seedless plants is that they put their energy into flowering instead of setting seed. With Double Play Doozie Spiraea, this results in a spirea that flowers all summer long. 

Double Play Doozie spring foliage

Double Play Doozie the first ever continuous blooming spirea

This plant is a game changer in the landscape market because it is so easy to grow and because it looks just as good in flower in August as it does in June when it first flowers. There is no need to shear it to get it to rebloom. The new growth continues to produce flower buds and flowers that cover and hid the older flower heads. The flowers are a vivid dark pink making it the perfect plant to replace ‘Anthony Waterer’ a variety that should have been discontinued year ago because it is a virus infected cultivar.  

Double Play Candy Corn® (Spiraea japonica ‘NCSX1’), is another Tom Ranney triploid hybrid, but it is not noted for being a rebloomer. This plant variety was selected for its unique colorful foliage. In the spring the first flush of foliage emerges a fiery orange-red. As spring progresses, the foliage color changes to a bright yellow and then eventually to a butter yellow, while constantly being accentuated with bright reddish-orange hues in the new growth. The color combination is quite unique and pleasing. The name Candy Corn, pays tribute to a sickeningly sweet, American, Halloween candy noted for its bright orange and yellow colors. 

The foliage transition of Double Play Candy Corn 

There is one more spirea in the Double Play series that is not a Spiraea japonica, but rather a selection of Spiraea media, a species that is native to Eastern Europe. A number of years back we use to grow and sell a Darthauzer nurseries variety named Snowstorm™ (Spiraea media 'Darsnorm'). After three or four generations of inbreeding and selection we singled out a dwarf plant with notable blue foliage. We introduced it with the name Double Play Blue Kazoo (Spiraea media ‘SMSMBK’) a silly, but memorable name based on the silly children’s musical instrument. I love plants with colorful foliage and especially blue foliage and I believe this is a special plant. It is a low mounded, beauty with waxy, blue-green foliage that is randomly air-brushed with a cast of purple hues. The large, white, spring blooms contrast wonderfully with the richly colored foliage. Like all spirea, it looks best when planted en masse.

Double Play Blue Kazoo foliage

Blue Kazoo planting in bloom

It is a bit humorous looking back, because so many people told us we were wasting our time breeding Spiraea. They said, “Who needs another spirea?” But like all plant breeding, there is always room for new plants, if they are improvements. Growers continue to look for plants that finish faster and that have fewer production inputs. Retailers, with a limited number of salespeople, are looking for plants with greater impulse appeal, which will sell themselves. Consumers want shrubs that offer more than just two weeks of flowers. They are looking for reliable plants that earn their keep all season long and these new spirea do just that.

  

Get more information on each of the Double Play varieties here        

Taming Invasive Species

It is welcome news that lawmakers and the public now recognize the threat of certain exotic species which can displace our native species and alter our native ecosystems. Gardeners, nurserymen, landscaper architects and other land stewards need to act responsively to preserve our native habitats. No one wants to be responsible for the next purple loosestrife, kudzu, or multiflora rose, all well known examples of problematic species. The proverbial Pandora’s box has been opened, and now the question is how to close it.

Lawmakers have been scrambling to solve the problem of invasive plants. Banning plants “deemed invasive” has been the main tool utilized thus far. For example, the Ohio Department of Agriculture has just banned 38 plant species of plants. Banning these weedy, seedy plants should please environmentalists and gardeners alike because most have no commercial or ornamental value. But how do we address address plants that do have horticultural value? 

Plant scientists, horticulturists, farmers and gardeners have been breeding and selecting cultivars since the dawn of agriculture. Historically, cultivars have been developed to produce greater crop yields, larger fruit and bigger, more colorful flowers. But they have also developed breeding techniques to create seedless plants. We're all familiar seedless oranges, seedless watermelons and seedless bananas. So why not create seedless ornamental plants to solve the invasive plant problems? Researcher are!   

North Carolina State University researcher have been at the forefront of taming invasive species. Dr. Dennis Werner developed the Lo & Behold® series of butterfly bush (Buddleia) which was granted an exemption in Oregon where Buddleia has been banned because of its evasiveness in the Pacific Northwest.    

Black Knight butterfly bush (left) and Lo & Behold Purple Haze (right) 

Dr. Thomas Ranney, another plant researcher at NSCU, has developed two seedless cultivars of Japanese barberry (Berberis thunbergii). One of the cultivars, Sunjoy® Mini Maroon produces fruit, but just like navel oranges the fruit contains no seed. Sunjoy® Toto, another dwarf, dark leafed selection does not produce any fruit at all. Both Sunjoy® Mini Maroon and Sunjoy® Toto perfect replacements for the purple cultivars of  barberry that have been shown to be invasive in the Northeastern United States.

The fruit of Sunjoy® Mini Maroon barberry contains no seed rendering it non invasive.

Sunjoy® Mini Maroon - the environmentally friendly barberry. 

Comparison of female fertility traits among cultivars of Berberis.

Cultivar	n	Fruit Set (%)	Seeds/ Fruit	Germination (%)	Seedlings/ Flower	Relative fertilityZ (%)
Sunjoy Mini Maroon‘ NCBT1’	10	0.3 B	0.10 B	0.0 B	0.0 B	0.0 B
Sunjoy Toto ‘NCBX1’	5	0.0 B	0.00 B	0.0 B	0.0 B	0.0 B
‘Golden Devine’	5	33.8 A	1.15 A	38.3 A	0.16 A	71.3 A
‘Emerald Carousel’	8	42.7 A	1.26 A	41.1 A	0.22 A	100.0 A
2014
‘NCBT1’ Sunjoy Mini Maroon	10	37.4 B	0.09 B	23.3 B	0.003 B	1.2 B
‘Golden Devine’	4	66.0 A	1.30 A	30.3 B	0.284 A	100.0 A
‘Emerald Carousel’	8	33.5 B	1.13 A	56.4 A	0.220 A	77.6 A

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Cultivars such as these have the potential to, in part, solve the invasive plant problem, but in some cases states are banning them along with the culprit species. It’s frustrating because plant breeders are addressing this issue and their work is going to waste because people are simply uneducated. Legislators are throwing the baby out with the bathwater. 

At the moment few people seem to care about the cultivar issue because they don’t know that environmentally safe, seedless cultivars exist. Gardeners, like environmentalists, are proud of our natural heritage and want to preserve native habitats. They want to do what is morally right, but they also want to create beautiful gardens in our man made habitats. Cities and suburbs present challenging growing environments and some plants perform better than our native plants. 

There are others who do know about non-invasive cultivars and are content to keep quiet because they’re not gardeners and they don’t want to complicate the invasive plant issue. Their goal is to keep the process moving. And the process is moving fast. The question is “will gardening public wake up and smell the roses?” Perhaps, but it may be too late to make a difference, as states continue to ban environmentally friendly cultivars.

Gardeners and growers are not the bad guys and they need not be the losers. Non-invasive, seedless cultivars are the answer and not the problem in the complex issue of invasive species.

       

Hydrangea Heroes

The year 1823 was a significant year in annals of horticulture. A young, adventurous, German physician set foot on the man-made island of Dejima, a trading post for the Dutch East India Company, just off the coast of Nagasaki, Japan. Fresh out of medical school at age twenty-seven, Phillip Franz von Siebold, was looking for a bit of adventure and the Dutch East Indian Company offered him that opportunity as resident physician and scientist in Japan. He was to be the successor to Engelbert Kaempfer and Carl Peter Thunberg, two former resident physicians at Dejima, both also famous plantsman you may recognized from the specific epitaphs on a number Japanese plant species including Larix kaempferi and Berberis thunbergii.  

Herbarium specimen of wild H. paniculata

Essentially closed to all other Western scientists, Siebold excelled as a physician and botanist, while in Japan. His unique abilities as a cataract surgeon (along with his knowledge of and supply of belladonna used for dilating the pupil) gave him a freedom of travel afforded to few foreigners in this isolated country. Between his personal acquisitions and the gifts paid to him in kind for his doctoring and teaching, Siebold amassed over 1000 native Japanese plants in his back yard garden. In amongst these plants was Hydrangea paniculata (wild type) and Hydrangea paniculata ‘Grandiflora’ (aka PEE GEE hydrangea), both of which he sent Europe and are still today common landscape plants.

PEE GEE ~ Hydrangea paniculata 'Grandiflora' 

In my twenty-some years as a plant hunter, I’ve had some pretty unique opportunities. One of these was visiting the late Jelena DeBelder in the summer of 1996. We met at Hemelrijk, her family estate near Antwerp, Belgium. As she shuttled us about the grounds in her beat up VW Rabbit, filled with pots, shovels and plants, I soon realized I was in the presence of someone special. Her every word was filled with passion.  With the pride of a mother she introduced us to her hydrangeas: ‘Pink Diamond’, ‘Unique’, The Swan, ‘Burgundy Lace’, ‘White Moth’ and her personal favorite ‘Little Lamb’. “This is a very special plant,” she told us, “Little lambs dancing about in joy. Very special.”  

Jelena DeBelder schooling me on hydrangeas

Soon after I met the renowned plantsman Pieter Zwijnenburg. At the time, Pieter and his wife Anja had a small nursery in Boskoop area of the Netherlands. The “Heronswood of Europe” his nursery offered over 2500 different varieties of trees and shrubs. In his career Pieter has introduced over 50 different new plants. On this particular day he showed us his newest development, a new Hydrangea that would soon be named ‘Limelight’. And just down the road a few miles, on another day, Rein and Mark Bulk showed me their new, early flowering hydrangea that had volunteered in his nursery. In a few years, we’d introduce this one as Quick Fire® Hydrangea. 

Pieter and his wife Anja

Still later and to the south, we and the world came to know Dr. Johan Van Huylenbroeck of the Flanders Research Institute for Agriculture. Johan’s outstanding Hydrangea paniculata breeding would give us Mega Mindy®, Pinky Winky® and Bobo®.  

Dr. Johan Van Huylenbroeck with the original Bobo®

Meanwhile in France, Jean Renault was also breeding Hydrangea paniculata which would yield Vanilla Fraise®, aka Vanilla Strawberry™.  

Jean Renault

And back home in Grand Haven, Michigan, while standing on the shoulders of all these giants, I had a hand in the development and introduction of a few good hydrangea paniculata plants as well: Little Lime®, Little Quick Fire®, Pillow Talk®, Fire Light® and Zinfin Doll®.

Zinfin Doll® in our stock block

Next year we'll introduce three, exciting new selections. Fire Light Tidbit™ is front of the border, dwarf, 2-2.5’ mounded selection with creamy white flowers that take on strawberry pink hues as the summer progresses towards fall.    

Fire Light Tidbit™

Fire Light Tidbit™ 

QuickFire Fab hydrangea is in a class of its own when it comes to color. The delicate, cruciform flowers emerge green, transition to white and then start turning raspberry pink from the bottom up producing a unique two-toned look.

Quick Fire Fab™

Early blooming Quick Fire Fab™ hydrangea

And now, even ‘Limelight’ has gotten better. Limelight Prime™ has stronger stems that eliminate bloom flopping. It has dark, forest green foliage, unlike ‘Limelight that is prone to yellowing with chlorosis. And Limelight Prime™ has predictable autumn flower color. 

Limelight Prime™ Hydrangea

Autumn hues of Limelight Prime® hydrangea

Me oh my, how this once unassuming Japanese hydrangea, introduced over one hundred and fifty-seven years ago, has changed and improved. We now have cultivars with stronger stems that do not flop. We have dwarf selections and early blooming selections. We have green flowers and flowers that age with hues that range from green to bubblegum pink to rich pomegranate red. We have big flowers and small flowers, full flowers and lacy flowers.

It has been over a one hundred and fifty-seven years since Pee Gee hydrangea was introduced by Dr. von Siebold. Plant breeding and selection continues to improve our plants, generation after generation and we should all be proud of the role we play in this evolution. Sure I know, it’s disruptive, but all change is. And yes, along the journey there have been some plants that should not have be introduced. No one is perfect. Not all of Apple’s product launches have been a success. Remember the Newton? In fact, most all of their product introductions are no longer sold! Does this mean that Apple should slow down or stop innovating? Of course not. We are living in the Golden Age of technology. We are also living in the Golden Age of plant breeding. Buckle up and enjoy it! It going to get even better.