Clethra: The Sweetest Summer Shrubs

I distinctly remember my first encounter with Clethra alnifolia (Summersweet or Sweetpepperbush). The air was thick with its spicy sweet fragrance and it begged me to search for it source. Tucked into the center of a large shrub boarder was a tall, gangly plant with small white spires about eight feet in the air. Not much of a plant, but it was obvious that it had never been pruned or cared for. Despite its poor habit, I felt that any plant that smelled that sweet deserved to be used. Some years later I specified Clethra in a landscape design. Of course I was a naïve greenhorn, too foolish to realize that it was not available in the trade for purchase. But I was smart enough to realize it was a plant worth growing.

Times have changed and so have our pallet of plants. Today Clethra is available to purchase at nearly every landscape pick-up yard, so are a host of improved cultivars. How is it that within a period of 25 years, so much can change?

It all started with Clethra ‘Hummingbird,’ the first dwarf form of Sweetspire. It was an obscure plant that Fred Galle of Callowway Gardens had discovered and for the most part had been forgotten. Then Richard Feist, a Callowway intern at the time, saw the plant and bells went off. With the permission of Galle he registered the plant as ‘Hummingbird’ and then wrote an article in Field Notes in American Nurseryman. All of a sudden Clethra was worthy. Clones started coming out of the woodwork; ‘Rosea’, ‘Pink Spires’, ‘Creal’s Callico’, ‘Fern Valley Pink’, ‘Hokey Pink’, ‘Cottondale’, ‘September Beauty’, ‘Ruby Spice’, ‘Sweet Suzanne’, ‘Sixteen Candles’, ‘White Dove’ and ‘Sherry Sue’ just to name a few.

While Clethra is relatively easy to fine these days, it is still greatly under used. In my travels to Europe, I am amazed that the plant has gained little respect; it is available only at collector type nurseries. How can it be?

Summersweet is an American native that can be found along the Eastern seaboard from Maine to Florida and west into Texas; along its western range it is native as far north as Tennessee. As a facultative wetland species is most likely to be found growing in low, moist woodlands, especially in the South, but in its northern range it is not unlikely to find the plant on higher, drier ground. You need not plant this shrub in a swamp to have success. My garden is nearly pure sand, and with the regular irrigation the plant grows just fine. Just remember that Clethra is not a plant for droughty soils. USDA zones 5-9.

Plant height varies greatly depending upon the cultivar. While the species can reach eight feet in height, cultivars such as ‘Hummingbird’, ‘Sixteen Candles’ and White Dove™ max out around three feet. Regardless of cultivar Summersweet benefits from pruning especially at a young age. Regular pruning creates a bushier, fuller plant as opposed to a leggy bare bottomed plant. Clethra alnifolia, especially the variety tomentosa can be suckering or stoloniferous. My observation has been that suckering is more prevalent in moist soils, while it is almost nonexistent on drier soils. Even where suckering is prevalent, it is never so aggressive that it presents a problem.

Flowers while typically white, can also be pink (‘Pink Spires’, ‘Hokey Pink’, ‘Rosea’) or near-red, dark pink such as ‘Ruby Spice’. The light pink varieties are quite attractive and should not be abandoned totally in favor of the darker ‘Ruby Spice’; even though the flowers may fade to near white as they age it is still a pleasing pink in the garden. The blooms appear in late summer; in Michigan we begin to see flowers in late July with August being prime bloom time. The cultivar September beauty™ extends the flowering season several week later than the other cultivars. Leave color ranges from a grey-green (‘Cottendale’) to dark green (Hummingbird, September Beauty, Sixteen Candles and White Dove™) with most other cultivars falling somewhere in between.

A check list of Cultivars:

‘Anne Bidwell’ - Panicle inflorescence with multiple racemes. Selected by Anne Bidwell.

‘Cottondale’ (var. tomentosa) - A selection with very large racemes up to 16” in length and grey-green leaves, suckering. Selected by Woodlanders Nusery.

‘Compacta’ - A very attractive selection with compact branching and a rounded habit of about 4’ in height. Selected by Tom Dilatush.

‘Creels Calico’ - A suckering plant with highly variable variegation. More of a curiosity than a landscape plant. Selected by Michael Creel.

'Fern Valley Pink' - Long, light pink flowers. Selected by Tom Clark.

‘Hokie Pink’ - Light pink flowers, more compact than typical. Selected by Jime Monroe.

‘Hummingbird’ - A low, compact, mounded plant maturing around 3’. Very dark green foliage and good yellow fall color. Selected by Fred Galle.

‘Pink Spires’ - Light pink flowers, matures at 6’-8’.

‘Rosea’ - Very similar to Pink Spires

‘Ruby Spice’ - A sport mutation of 'Pink Spires' with red flower buds that open to a rich pink. Does not fade to white. Very good yellow fall color. Selected by Andy Brand.

‘Sherry Sue’ - Typical white flowers, young stems are an attractive cherry red. Brought to us from the J.C. Raulston Arboretum.

‘Sixteen Candles’ -A seedling of Hummingbird with tight growth and larger white flowers. A fine plant selected by Mike Dirr.

‘Sweet Suzanne’ - Another seedling of Hummingbird with large flowers. Has been a weak grower for us, not as good as above. Selected by Mike Dirr.

var. tomentosa -A suckering plant with grey green leaves. ‘Cottondale’ is a superior selection

White Dove™ - Another seedling of Humingbird, Compact habit and larger white flowers. Selected by Flowerwood Nursery.


Related Species:

Clethra acuminata: Cinnamon Pepperbush - A small tree or larges suckering shrub at 12-15' in height. White flowers borne in termial racemes, with only slight fragrance. Attractive cinnamon colored bark. USDA Zones 6-8.

Clethra barbinervis: Japanese Pepperbush - A small tree or large shrub 15'-20' in height. White, fragrant flowers in terminal panicles in mid-summer. Superb exfoliating bark. An excellent plant for USDA Zones 6-7.

Behind the Iron Curtain

Poland stirs my soul. The people are warm and loving. The food is superb, yet unpretentious (The mushroom porogies were unforgettable). It is a country of many contrasts. I am struck by the difference between the stark cement Soviet architecture of Warsaw and the old world beauty of Krakow. I feel the pride and triumph of Lech Walesa and the sorrow and cries of Auschwitz. But more than anything I feel Poland’s enduring love for freedom.

For decades, little was known about the nurseries of Eastern Europe and what plants they were cultivating there. There were rumours of Syringa (Lilac) breeding in the Soviet Union and of vast conifer collections in Czechoslovakia, but few if any Eastern plants defected and turned up in the West. With the fall of the Soviet Empire and the Iron Curtain the door was opened to discover what if anything might be found in Eastern Europe. From a cultural and climatic standpoint my greatest hopes were in Poland, East Germany, The Czech Republic and Hungary. Of these, Poland was the most interesting. Its people had a reputation for plants, gardening and hard work. Since the fall of the Iron Curtain Poland lead the East in the importation of nursery stock and cut flowers. Clearly the Polish people had an appreciation for plants. It was my hope that a nursery culture and perhaps even an underground nursery industry had survived the cold war.

Mateusz Milcznska was our key to Poland. A former intern at Spring Meadow, Mateusz volunteered to be our guide and translator while touring Poland. He spoke excellent English and he had the driving skills essential for navigating the narrow and hectic roads of Poland. Mateusz had arranged all of our appointments including of our most pleasant surprise, the nursery of Lucjan Kurowski. One look at Lucjan Kurowski’s nursery and you could tell he had a passion for plants.

Mr. Kurowski established his nursery in 1960. Initially it was started on a small acreage and his market was limited to his local area. Over the years the nursery prospered and had grown to its current size of 24 hectares, which includes 12 hectares of container plants and 4 hectares of in-ground plants. The fall Iron Curtain had a dramatic effect on his business and as a result Lucjan now exports to Russia, Ukraine, Sweden, Norway, Finland, Lithuania, Belarus and Hungary.

We were surprised at the quality plants at Lucjan’s nursery and we were especially surprised by the mix of plants he was growing. All of the latest Western introductions were there. He had wasted little time in accumulating the best new plants from the West. We were also delighted to learn he had active breeding program and had even introduced five of his own selections.


The one plant that caught our eye was a narrow upright barberry with bright golden foliage called SunjoyTM Gold Pillar Barberry (Berberis thunbergii ‘Maria’ ppaf). Adding to its appeal, hues of red and orange tinged the new growth. In essence it is a golden version of Helmond’s Pillar. With Mateusz translating, Lucjan explained that his selection was more than just beautiful; it was also extremely burn resistant - a bonus because most gold leaved variates burn in full sun. Lucjan showed us the proof; Sunjoy Gold Pillar was the only clean plant in a full sun test bed that included all the latest varieties.

While the discovery of Sunjoy Gold Pillar made our trip to Poland a success, importing it was whole new challenge. The problem is that some species of Berberis are host to a disease called Wheat Rust. While Sunjoy Gold Pillar and all other selections of Berberis thunbergii are resistant to wheat rust, Federal Law prohibits the importation of cultivars that are not listed as certified rust resistant. Obviously this plant was not on the list. The catch 22 was we had to import the plant in order to have it tested, but we could not import it because it had not been tested. With a bit of hard work and a lot of luck we were able to import the plant directly to the Federal Wheat Rust laboratory and after two years of testing and yet another two years to get the plant published on the Federal list, we are now able to offer this plant legally in the United States. While the entire process took over six years, it is exciting to see that our trip to the former Eastern Block was a success.

Getting a new plant can be a struggle, but it is nothing compared to the struggles Poland has endured to gain its Liberty. Still - I find satisfaction in both and I am not alone. According to Thomas Jefferson "The boisterous sea of liberty is never without a wave” and “The greatest service which can be rendered any country is to add a useful plant to its culture."

Ban All Plants!

State, Federal and local lawmakers have been scrambling to solve the problem of invasive plant species. Unfortunately for the American gardening public, one of the best solutions to the problem is being completely ignored; creating, promoting and growing cultivated varieties (or cultivars) of these species that do not possess invasive characteristics.

Plant scientists, horticulturists, farmers and gardeners have been selecting and breeding cultivars since the dawn of agriculture. Historically, cultivars have been developed to produce greater crop yields or larger, more colorful flowers. These same techniques can and have been used to produce well behaved, environmentally friendly plants that are not invasive threats like their parents.

It is welcome news that lawmakers and the public now recognize the threat of certain exotic species which can displace native species and alter our native ecosystems. Gardeners, nurserymen, landscaper architects and other land stewards need to act responsively to preserve 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; now the question for lawmakers is how to close the box.

Banning the sale and production of plant species “deemed invasive” is the approach under consideration by some states. For example Connecticut is on the verge of placing restrictions on roughly 70 plant species. Banning most of these weedy, seedy plants would please environmentalists and gardeners alike. Most have no ornamental value with the exception of Burning Bush (Euonymus alatus) and Japanese barberry (Berberis thunbergii) two very popular garden plants.

Should gardeners, landscapers, nurserymen and garden centers be forced to forgo some of their best performing plants? The question could be irrelevant, if lawmakers would only recognize how relatively easy it is to tame these species. Many environmentally friendly cultivars are already available, but are, or will be, banned by unknowing legislators. One example is Common buckthorn Rhamnus frangula. Most would agree that the species, which has a germination rate in excess of 95%, is an invasive threat. One would be hard pressed to say the same about a new buckthorn cultivar called Fine Line™, grown for it attractive lacy foliage and distinctly narrow habit. Fine Line is not an environmental threat because it is nearly impossible to grow from seed. Even under ideal university conditions, germination studies yielded a meager 6% germination rate. There are also environmentally safe cultivars of Burning Bush and Japanese barberry. Rarely will you find a seed on the dwarf Burning Bush cultivar ‘Rudy Haag’ or the dwarf purple Japanese Barberry cultivar ‘Concorde’ but this may be irrelevant in states that don’t recognize the genetic diversity of plant species and the potential of breeding. Cultivars that have the potential to, in part, solve the invasive plant problem are being banned along with the culprit species.

Gardeners need not feel guilty for growing exotic plants, if they are environmentally safe cultivars. It’s frustrating because plant breeders across the country 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. Cultivars are part of the solution and should not be labeled as “outlaws” just because their parent species are problematic.

At the moment few people seem to care about the cultivar issue because they don’t know that “safe” 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 exotic plants often perform better than native plants. Contrary to popular dogma native plants are not more adaptable than exotic species. And they are not more resistant to insect and disease attacks. Quite the contrary; exotic species are often used by plant breeders to create new pest resistant cultivars that do not require the use of pesticides.

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 and 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. States continue to ban species of plants along with popular cultivars that pose no threat to the environment.

Now imagine the police showing up at your door and fining you $100 for each rose in your yard. It may not be as outlandish as it sounds. Many popular disease resistant roses were derived from the outlaw multiflora rose. There’s even a good chance it’s the rootstock on your prized tea roses as well. Combine this with the intent of Connecticut House Bill 5614 which proposes a $100 fine per violation (50 plants could be 50 violations) and you get the picture. Perhaps it’s time for a little common sense dealing with the problem of invasive plants. Gardeners and growers are not the bad guys and they need not be the losers. Cultivars are the answer and not the problem in the complex issue of invasive species.

California Pack Trials - A Pleasant Surprise

I just got back from the California Pack Trials and have the sunburn to prove it. This was my first visit to the Pack Trials and it proved to be a very interesting experience. If you are not familiar with Pack Trials, it is a week long event where some forty different breeders and growers showcase their new plant introductions. Attendees travel the coast of California making stops at greenhouses and display gardens to get the inside scoop on what’s new for the coming year. In the past, the Pack Trials were almost entirely dedicated to seed grown annuals and growers would come out and evaluate how the new annuals presented themselves in trays or cell “packs.” Times have changed and very few if any plants are seed grown and the plants are no longer displayed in trays.

For me Pack Trials was an opportunity to gage people’s reaction to new introductions. What is it that really gets people talking? I have never had much belief in focus groups when it relates to plants. I much prefer to go to a garden center and play detective. What are people putting in their carts? What are the plants that draw the attention of people in the store? The same is true for pack trials. It was interesting to see which plants got people excited.

At the Proven Winners display located at EuroAmerican Propagators, just north of San Diego, I was amazed at the reaction that people had towards the new line of OSO EASY roses – (Oso Easy ‘Peach Cream,’ Oso Easy ‘Fragrant Spreader,’ and Oso Easy ‘Paprika’) Prior to this, I had been repeatedly told that it was the absolutely worst time to introduce roses. Keep in mind that only one week ago, the leading name in roses - Jackson and Perkins was sold. The mighty have fallen, because the rose industry is in a fast, deep downward spiral. No one wants tea roses or grandifloras any more. Gardeners refuse to spray roses. For better or worse, growers and retailers have become fixated on ‘Knockout’ roses, just as they had done twenty years ago with ‘Stella d’Ora’ daylily. The herd mentality of the nursery industry is alive and well, so it was a pleasant surprise to watch the reaction of growers and retailers when presented a new line of roses. There was genuine excitement in eyes of everyone as they first caught a glimpse of the Oso Easy Line - And why not? These are great roses.

I know how good these roses are because I have been evaluating them for the last five years. I get test roses from five different rose breeders and I have tested countless selections - but only these three plants have made the grade. Our nursery grows many roses, and most all of them are a grower’s nightmare. For roses to go through the high heat and humidity of our propagation and production system and to stay clean is nearly impossible. Unlike the All American Rose testing process, we do not spray our test roses; not in the ground and not in production. Undoubtedly these are darn good roses. But to see buyers, growers and retailers get excited was confirmation that these roses have a bright future despite the bleak state of the rose industry. It was a pleasant surprise.

Flowering Shrub Evolution - Part II

Lo & Behold Dwarf Butterfly Bush

In my last post I wrote about new breakthrough plants that have changed the evolution of flowering shrubs. This post continues the discussion, and I've listed the shrubs that I think have changed the way we think about, and use them in our gardens and landscapes.

Have I left anything off the list? Send me your thoughts and comments.

Plant Name - Significance to the Industry

Abelia mosenensis
A Zone 4 Abelia with better fragrance than Viburnum carlesii

Berberis thun. ‘Concorde’
Dwarf, grape purple foliage, that’s nearly sterile

Buddleia davidii
English Butterfly Series™
A new series with dwarf growth. They actually look good in a one gallon.

Buddleia Lo & BeholdA new dwarf  series of Buddleia. Sterile.

Caryopteris incana Sunshine Blue®
A hardy, strong growing Caryopteris with bright yellow foliage and rich blue flowers. Move over Worchester Gold. Move over Gold Mound Spiraea?

Caryopteris Petit Bleu™
A dwarf Caryopteris with dark glossy leaves

Clethra ‘Hummingbird’
Sixteen Candles may be the best, but it was Hummingbird that started it all.

Clethra ‘Ruby Spice’
Andy Brand discovers the first pink Clethra that actually stays pink.

Corylus a. ‘Red Majestic’ pp#16,048
The first contorted filbert with red foliage. Year round excitement.

Deutzia gracilis Chardonnay Pearls®
The first Deutzia with season long color. Bright lemon yellow foliage rivals Spiraea

Diervilla ‘Butterfly’
Landscaper know the Diervilla is as tough as nails but Butterfly is attractive enough for retail

Euonymus alatus ‘Rudy Haag’
Grow this dwarf selection to be environmentally proactive in the fight against invasives.

Forsythia ‘Golden Peep’
Who has room for a 12 foot Forsythia? Not me, nor do many people. This is a great plant for around the deck

Fothergilla major ‘Blue Shadows’
A blue leafed Fothergilla that actually lives. Yes it’s true. Gary Handy discovers a Blue Mount Airy.

Hibiscus syriacus Chiffon™ Series
A vigorous rose of Sharon that will make money for nurseries and flowers like crazy. Unique Lacy flowers

Pink Chiffon

Hydrangea arborescens ‘Hayes Starburst’
A first! Hayes Jackson discovers a double flowered form of arborescens.

Hydrangea Endless Summer™
Great news for us in the Midwest with Hydrangea envy. Blooms on new wood. More to come.

Hydrangea paniculata ‘Limelight’
A Pee Gee with bright green flowers, strong stems. Does not flop like Pee Gee and finishes fast.

Hydrangea paniculata Little Lime
The best. A dwarf with strong stems and full flower heads

Little Lime

Hydrangea paniculata Quick Fire™

Why wait until August for Blooms. Quick Fire flowers in June and turns pink before Pink Diamond even flowers.

Hydrangea ‘Snowflake’
The best oakleaf with it doubled, hose in hose blooms that turn pink as they age. Very healthy and great fall color.

Hypericum ‘Blue Velvet’
Blue Leaves on a Hypericum, yes. Paul Cappiello delivers a hit.

Indigofera ‘Rose Carpet’
Rich pink blooms from Late June until frost. Hugs the ground like a rug. I mean carpet.

Itea Little Henry®
The first dwarf Sweetspire.

Kerria ‘Honshu’
A hard to find Kerria with big flowers and superior stem hardiness. The only selection with fragrant flowers.

Leptodermis oblonga
A neat little known treasure with vivid pink flowers that keep on coming all season long.

Physocarpus Diabolo®
The first ninebark with purple foliage.

Physocarpus Summer Wine®
The first compact ninebark with purple foliage. Who has room for a 15 foot ninebark? Not me. A cross between Diabolo® and ‘Nana’.

Physocarpus Coppertina™
The first ninebark with orange red foliage.

Potentilla Pink Beauty
A pink Potentilla that actually comes out pink and lives more than a year.

Rhamnus Fine Line®
An environmentally friendly Rhamnus with cut leaves and narrow columnar growth. Remember how many Tall Hedge you used to sell.

Rosa Knock Out®
It proved that a rose can be grown without having to spray

Rosa Home Run®
The most disease resistant, most attractive rose on the market. Comes in Red and Pink. 

Rosa Morden Sunrise
Yes, a strong growing, healthy yellow rose.

Sambucus Black Beauty™
The first black leaf elder with pink flowers.

Sambucus Black Lace™
The first cut leaf black elder with pink flowers. Incredible texture. As elegant as a Japanese Maple.

Sambucus ‘Sutherland Gold’

The best yellow leafed elder.

Spiraea ‘Gold Mound’ / 'Goldflame'
The plant that started it all. Lime Mound was first but never caught on.

Spiraea Pink Parasols®
The first pink flowered Spiraea fritscheriana. Ground covering habit. Landscapers forget about Rhus ‘Gro-low’ this plant is great for mass planting and it has large pink flowers.

Thuja Spring Grove®
A hardy northern selection that is deer resistant.

Viburnum ‘Cayuga’
An improved fragrant Viburnum with disease resistance.

Viburnum Cardinal Candy™
The best plant in the garden in late summer. Loads of tightly packed cardinal red fruit. No pollinator necessary.

Viburnum nudum BRANDYWINE™
A new variety that does not need a pollinator to enhance fruit set.

Viburnum plicatum ‘Popcorn’
A hardy, heat tolerant snowball Viburnum.

Viburnum p. tomentosum ‘Summer Snowflake’
What’s better than a Viburnum? A continuous blooming Viburnum

Viburnum ‘Mary Milton’
A Snowball Viburnum with pink flowers.

Weigela Midnight Wine®

The first dwarf purple leafed Weigela.

Weigela My Monet™
The first dwarf variegated Weigela. Very hardy, bright pink

Weigela 'White Knight’
The best reblooming Weigela. White flowers with a touch of pink.

Weigela Wine & Roses®
Dark burgundy foliage and vivid pink flowers.

Flowering Shrub Evolution

As the Product Develop Manager at Spring Meadow Nursery my main responsibility is to identify new and superior plants for the Proven Winners ColorChoice flowering shrub line. These are exciting times for me because never before has so much effort been put into the development of shrubs. Breeders, nurseryman and even amateur gardeners have begun to see the potential of shrubs and are actively seeking improvements. In my opinion the results are amazing. These new plants are changing the way we garden, landscape and produce plants. Long thought of as the “bones” of the garden, shrubs are now the ornamentation too. Once the backdrop for perennials and annuals, a new breed of flowering shrubs have proven themselves as colorful and as showy as any herbaceous plant.

Think for a moment about how Endless Summer has changed the way we view Hydrangea or how Wine & Roses has influenced our old perception of Weigela as a one season plant. These are but a few of the better known examples but there are many more subtle, yet significant changes taking place over a wide range of species. Growers and Retailers need to understand these changes if they hope to benefit and meet demand. For example when I googled the plant name Leptodermis oblonga three years ago I got zero responses. Today I got 1,710 references including long discussions about the plant by gardeners communicating in forums. Did you know this great little shrub that blooms all summer long? Obviously the word has gotten out to gardeners.

Not all of the plants causing shifts in the market are new. Some have been around for years but because of changing times have found an audience. Concorde barberry was an obscure little plant developed at Wavecrest Nursery in Fennville, Michigan. Now with the increased interest in invasive species and as the problems encountered on the East Coast mount, ‘Concorde’ turns out to be a winner. Not only does it have great rich purple leaf color and a dwarf mounded habit, it is also environmentally friendly, hardly producing a seed. It turns out there are many environmentally safe alternatives when we start looking at the cultivars we currently grow. This niche will get even larger as researchers begin to introduce new sterile cultivars. They’re coming, but will states ban them before they are introduced? Let’s hope not.

What’s driving this explosion of new and improved shrubs? First, there is intense competition at retail. Savvy independent garden centers know they have to differentiate their stores from the big boxes. New and improved plants are a clear strategy to set a garden center apart from the chains. Big box stores have been more concerned about price than the actual product. They won’t pay extra for superior genetics because they don’t understand plants in general. Heck, many have not yet figured out that plants need water to live. The point is that independents understand what makes a good plant and they are actively looking for new products to compete and win in the marketplace.

The second driving force behind new plants has been the increased use of plant protection. Plant breeders can now make a return on their breeding investment. Canada has a new breeders’ rights law and Europe now has EU wide breeders’ rights system. In the U.S., people who have long opposed the plant patent system now see that patents, if used properly, can benefit everyone. Open licensing and returning a portion of the royalties to marketing the plants have created new value for breeders, growers and the retailers. And gardeners are getting better plants.

Another driving force behind the development of new shrubs was the rapid growth of the perennial market. Perennials helped to grow a new crop of gardeners, particularly women gardeners. Before perennials, the yard was mostly a man’s domain. As perennials came into vogue women learned that the garden could be more than just annuals and that gardening was not as complicated as the books and magazines make it out to be. As the perennial market matured, shrubs were the next natural step. After all shrubs are perennials, they just happen to have woody stems. The advent of container grown shrubs also helped the cause. Clean and reasonable in size, containerized shrubs met the needs of today’s gardener.

Lastly, success drives success. The success of new shrubs has awakened plant breeders, nurseries, retailers and gardeners to the value of flowering shrubs. Reblooming Viburnum, dwarf Clethra, ground covering Forsythia, yellow Spiraea, purple Sambucus, dwarf Buddleia and reblooming Syringa are just a few of the recent advances. It often starts with one new plant and builds rapidly. When I was in college some 25 years ago people laughed at me for putting Clethra alnifolia in a landscape plan. Then along came Clethra ‘Hummingbird,’ the first dwarf form of Sweetspire. It was an obscure plant that Fred Galle of Callowway Gardenshad discovered and for the most had part forgotten. Then Richard Feist, an Callowway intern at the time, saw the plant and bells went off. With the permission of Galle he registered the plant as Hummingbird and then wrote an article in Field Notes. All of a sudden Clethra clones start coming out of the woodwork; ‘Rosea’, ‘Pink Spires’, ‘Creal’s Callico’, ‘Fern Valley Pink’, ‘Hokey Pink’, ‘Cottondale’, ‘September Beauty’, ‘Ruby Spice’, ‘Sweet Suzanne’, ‘Sixteen Candles’, ‘White Dove’ and ‘Sherry Sue’ just to name a few. And so it goes with most species. Just wait until you see the next generation of reblooming Hydrangea macrophylla. Dr. Michael Dirr and breeders around the world are working like mad to improve upon Endless Summer. And so it goes, we are all winners because plants are improving at an exponential rate.

New and superior plants and the fundamental changes taking place in the market represent opportunities for nurseries and garden centers. There is real unfulfilled demand for superior varieties and consumers are willing to pay extra for them. The most commonly asked question I hear from retailers and from gardeners is “Where can I find them?”

In my next post I will list some plants that have had or will have a significant impact on the shrub market. These plants are changing the way we view shrubs. Check back next time and find out how many of these plants you know.

More Notes From France

Forsythia has a Bright Future

One of my favorite nurseries in France is Pepinieres Minier. Located in Loire Valley, the nursery dates back as far as 1838. Since that time it has grown into one of the leading nurseries in all of Europe. While they grow a wide range of garden plants, they specialize in Hydrangea, Magnolia, Syringa (Lilac) and in Hibiscus (Rose of Sharon). Violet Satin Hibiscus and Rose Satin Hibiscus are two many outstanding plants developed by Minier.

The driving force behind the nursery is Jean-Paul Davasse, a quiet, unassuming man that just happens to be a first rate plantsman. Not only does Jean-Paul oversee 270 employees and some 250 hectares of production he make the time to manage Minier’s breeding program.

Our recent visit to Minier took us back their superb display garden and as always, Jean-Paul beamed with excitement as we zigzagged the garden looking at their newest acquisitions and breeding work. Fortunately spring came early to the Loire this year and we were lucky enough to evaluate his Forsythia collection.

While Forsythia is not their specialty per say, Jean-Paul has a keen interest in the plant and has been actively breeding the plant for some time. The gem of the collection was his own development, Show Off (Forsythia ‘Mindia). This beauty originated as a sport from the compact, variegated cultivar ‘Fiesta’. There are several notable attributes that makes Show Off special; in the spring it is loaded with very bright, very large flowers that emerge from the base of the plant to the very tips of its branches. Most forsythia plants grow indeterminately, and thus flower buds often fail to form on the late season growth. Show Off seems to have no such problem. While outstanding in the garden, Show Off is especially showy in the garden center. It shines in a three gallon pot compared to other selections. This plant is also quite attractive later in the season because of its compact form and its unusual dark green leaves. The leaves are darker than any other cultivar and distinct in shape as well.

After the garden, we had the great pleasure of evaluating his latest crop of unnamed, unreleased forsythia seedlings. He had narrowed the breeding work down from 3,000 seedlings to about thirty selections. These selections were now in three gallon pots, as well as, in field plots. The evaluation process is the most exciting part of the breeing process. It is also the most difficult part – so many beautiful plants to choose from and you have to narrow the field down to one or two plants that are significant and worthy of introduction. In other words, you have the fortitude to throw plants away! During our evaluation we looked at flower size, flower color, plant density, dwarfness, the flower bud density and overall presentation. So many superb plants, but clearly one or two unique and superior selections rose to the top. Plants destined to have a bright future.

Some say that Forsythia is old fashioned and over used. Some would even say it’s boring - but I strongly disagree. And if you were in my shoes this day, evaluating Jean-Paul’s plants, you would feel as I do - forsythia has a bright future.

The “Apocalypse” at the Chateau d' Angers

In many ways I am fortunate that I have a job that takes me around the world looking for new plants, but many people including my wife think my travels are vacations. Contrary to popular belief, I do work very hard on these trips. It is not uncommon to visit nurseries and breeders from sun up to sundown for seven days straight. And in all my travels, I have yet to see the Eiffel Tower, Big Ben, or the Red Light district in Amsterdam.

That being said, once in a while we do find ourselves without any appointments, and if we can’t find any garden centers in the area; we do take in the local sites. We had such a day while in Angers, France. We took a day off to visit the Chateau d’Angers, a fortress that dates back to the 13th century.

While castles in France are as abundant as wine, it was highly recommended that we visit the Chateau d’Angers; - not so much for the building itself, but rather to see the tapestry. Housed within this fortress is the “Apocalypse,” the oldest tapestry of its size in the world. Commissioned in 1373, this fantastic work of art measures a massive 10,764 square feet in size. It is made up of 70 individual panels that, when viewed as a whole, tell the pictorial story of Revelation, the last book of the bible.

As you can see from the images below, this is an exceptional work of art. And in my option much more remarkable than the Eiffel Tower, Big Ben, or the Red Light district.

The Apocalypse tapestry - Angers, France

The Apocalypse tapestry - Angers, France

Hunting for plants has its rewards

Hunting for plants has its rewards. Dale and I just returned from a week long excursion to Northern France that took us from Angers, located in the center of the Loire Valley, north to the shores of Normandy. This begins the first of a series of short entries designed to make you all envious and jealous. Ah ... but that is the point – if I can convince you to leave the crowds and tourist traps of Paris for the magical French countryside - my job is done. Here you will come to know and love France. Skip Paris, are you mad? Yes I’m serious - think about it – do Europeans come to know America by visiting Los Angeles? I think not, so why not apply the same logic in our own travels abroad.

Guided by a beautiful French speaking woman that repeatedly shouted out “Tournez a gauche,” the handy GPS guidance system delivered us to the small village of Juvardeil located just north of the city of Angers. Here we set our base camp at the Chateau de la Buronniere, a quiet B&B with wonderful off-season rates. It is hard to say what was better, the majesty of the chateau or our sparkling innkeeper Willemien Van der Nat Verhage. Hard bread, dark coffee, and strong cheese greeted us each morning, while cold beer, red wine and assorted appetizers welcomed us home at night.

The Chateau de la Buronniere was, for the most part, built in the late sixteen hundreds, in the era of the Palais de Versailles. Parts of the home date back as far as 1450, and today it has no telephones, television and during our visit no other guests. We felt as if we had stepped back in time. What must it have been like to be the Sybille de la Buronniere, the original family of the chateau, living in such a grand house? Willemien told us that it was common then to entertain and to have numerous friends and guests for the summer months. There were no highways, cars, motels, televisions or x-box - but rather family, friends, food and good wine. Simple conversation, garden walks and fancy balls were the entertainment of the day.

For us, it was the perfect place to begin our plant hunting sorties into the rich Loire valley, home to numerous vineyards, pépinières (nurseries) and le Salon du Vegetal one of the most interesting horticultural exhibitions in Europe.

Kerria deserves a Second Look

Kerria japonica, The Japanese Yellow Rose, has been around for a long time. It has been sold for years, most commonly by low end mail order companies. For whatever reason, wholesale growers and garden centers rarely include this plant in their mix, and I wonder why? The more I see of this plant and what it can do in the landscape, the more I feel it deserves a second look. Please join me.

Kerria japonica is a hardy (Zone 5) deciduous shrub that matures at 3 to 5 feet in height. It's a dense mounded plant with numerous slender, zig-zagging branches that emerge at ground level. The beauty of Kerria is found in its flowers, stems and foliage. The bright yellow flowers are noticeable reminiscent of an old fashioned rose with its 5 petals. The flowers clearly make this plant a member of the Rosaceae family. In early spring, before the leaves emerge, the numerous yellow flowers create a colorful show. As an added benefit, Kerria will often rebloom off and on all summer long. The effect is beautiful and rewarding. Kerria is also blessed with attractive ornamental stems. From autumn to spring, its bright kelly green stems create a wonderful, fresh impression. Having visited the Cincinnati Zoo and Botanical Gardens in early spring a few years back, I distinctly remember big green drifts of Kerria. I was surprised and delighted to see it used throughout their beautifully landscaped grounds. Around every corner we were greeted by a mass of bright green. This unique combination of color and zigzagged lines creates a lasting impression.

You also have to appreciate the clean and simple foliage of Kerria. The leaves appear birch-like at first glance with its narrow triangular shape, but unlike birch, its leaves are brighter, doubly serrated, and display a pronounced puckering between the leaf veins. Always clean and green the foliage is a distinctive asset.

Culture

This is not a fussy plant that is difficult to grow or manage. Quite the contrary, Kerria is happy in most any reasonable well drained soil. It requires little fertility, and seems to flower best if neglected. Unlike other members of the rose family, Kerria has no serious insect of disease problems. The remarkable thing about this is that it thrives when grown in partially shaded to fully shaded locations. Few plants flower this well in shade! Full sun is also an option, but it does present a few problems. The flowers do not hold up as well and it can show some stem die-back if exposed to winter sun. Neither of these problems are severe, but both can distract from the beauty of the plant. It should be noted that this plant dislikes heavy, poorly drained soil. It will languish and grow smaller by the year. As far as ongoing maintenance, I personally feel this plant benefits from an occasional hard pruning. Cutting the plant to the ground produce a fuller plant, brighter stems and improved flowering.

The Cultivars

The most popular cultivar of Kerria is the old fashioned double flowered form, Kerria j. 'Pleniflora'. Its yellow button-like flowers resembles a chrysanthemum, and at peak bloom they polka dot the plant to create a distinct look. Kerria 'Pleniflora is not one of my favorite plants. To me it looks too contrived. I much prefer the simplicity of the single flowered forms. Two of the best single flowered cultivars are 'Honshu' and 'Golden Guinea'. I can detect only slight and inconsequential differences between these two plants. Both were selected for their large single flowers. If I had to choose only one of them I would pick ‘Honshu’ because its flowers are slightly larger and they have a soft and pleasing fragrance. The plant was introduced by Dr. Clifford Parks of Camellia Forest Nursery in Chapel Hill. Many people choose 'Golden Guinea' strictly because of its name. The name properly describes the size and color of the bloom. No the name Guinea does not refer to a bird or some exotic country, it refers to a large gold coin.

For those of you who need even more excitement in your life, several variegated selections are available. The best variegated type is called Kerria japonica 'Picta'. Not a great name, but a very good plant. Its leaves are graced with a creamy white margin that is not at all offensive like some variegated plants. The overall effect is very nice, and a decent specimen garners much attention. It does have its shortcomings. It can be slow growing when young making it difficult to produce especially when compared to the species. It also has a tendency to throw an occasional green shoot, which must be removed. This is a simple task and most gardeners would gladly pay this price to have such an interesting plant. I have seen another variegated clone under the name of 'Kinkan' or 'Auro-vittata'. This is worthless selection best left to the most ardent collector or relegated to the botanic garden. This "beauty" has green and yellow striped stems that tend to revert at the speed of sound and has small single yellow flowers.

While all Kerria selections have yellow flowers; the cultivar ‘Albaflora’ has blooms that are a near white, butter yellow. The color is more subtle, and I my opinion more pleasing to the eye than the typical bright yellow of the species.

Kerria is a beautiful plant with year long interest. Plant it in mass in a shady location and I think you'll be pleasantly surprised how nicely this plant performs. Very few flowering shrubs perform so well in the shade and you'll love the winter effect provided by its bright green stems.

Viburnum nudum: Close to perfection

Brandy Wine over three seasons

Possiumhaw or smooth witherod viburnum (Viburnum nudum) is a little known and underutilized shrub that is native from Maine and Florida and west into Texas. This is a remarkable shrub for several reasons; most notably for its attractive leaves that are so glossy you might think they’d been sprayed with leaf shine. As an added attraction the leaves turn to an eye-catching rich burgundy in autumn.


While attractive from a distance, the creamy-white, spring blooms are a bit uninteresting compared to other, more showy or more fragrant viburnums. To me its musky odor is neither pleasing or offensive - yet in late spring, the overall flower display is a welcome site in any garden. More importanly the flowers should be praised and respected for they give birth to an breathtaking fruit display that is unrivaled in the plant world.


In late summer the immature green, pea-sized berries (technically drupes) begin their metamorphosis - changing to shades of bright pink and then on to hues of bright blues and wild grape. The transformation is unsynchronized and yields large clusters of polychromic berries more showy than Donny Osmond’s dreamcoat.

Brandywine has colorful berries

While there is no such thing as a perfect plant, this one comes close. Still it is not suitable for all gardens. The species will not thrive on chalky or alkaline soils. In the North Eastern, U.S., Viburnum bark beetle can be a problem for this species, but fortunately these buggers can be controlled without chemicals. 


So how can such a beautiful plant escape full-blown stardom? As is the case with many Viburnum species, fruit set mandates that two distinct varieties (clones or ciltivars) are grown in close proximity to cross pollinate. And until the recent introduction of Brandywine™ (Viburnum nudum ‘Bulk’), most growers offered one cultivar called ‘Winterthur’ and it never set fruit. Brandywine was introduced by Proven Winners so that  there would be two selections available and thus allow for fruit set. It turns out, however, that Brandwine will set fruit without the need for another cultivar near by to cross pollinate. I have grown this plant for over four years and it has set fruit with a companion. 

Brandywine Fall color 

Brandywine Viburnum is hardy from zone 5(4) to 9. It prefers full sun to partial shade and moist, but well drained soil. It matures at a height and width of 5-7 feet. Once established it requires very little care yet offers so much more in return. 

The Gift: a passion for plants

While I spend most of my time looking for new plants, today I discovered some plants that were old but personally significant. My father sent me an email with a link to a website called Penny Postcards. On this site you can view old postcards arranged geographically by state and county. My father directed me to the cards for Linn County, Iowa. Here I discovered beautiful postcards of gardens designed by my late grandfather William Wood, the former manager of parks for Cedar Rapids, Iowa.

I’ve never met my grandfather. I am sad to say he died before I was born, but I do feel a closeness to William for like my father and me, he was a plantsman. He was trained in England as a true master gardener before he immigrated to the town made famous by Quaker Oats. I have visited the parks of Cedar Rapids many times and with each visit I was warmly greeted with the smell of cooked oats and the lasting remnants of William’s handy work; the Ellis Park golf course, the ruins of an old Shakespeare garden and trees planted by his caring hands. No, I have never met my grandfather, but still, I have come to know him. He loved plants and gardens, and he had a desire to share his passion with others, and that is the gift he gave to me.

Now you can subscribe to the Plant Hunter and get your updates by email.