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.    

Edible Honeysuckle

When we think of honeysuckle, we tend to think about richly colored, fragrant flowers on beautiful vines like 'Scentsation' (Lonicera periclymenum), which blooms all summer long and perfumes the air with a fragrance better than anything found in a bottle.  

If you live in the Eastern United States, you most likely think of Lonicera japonica, the weedy, tenacious Japanese honeysuckle vine that can be found in just about every fence row. 

But who would have ever thought of honeysuckle as an edible fruit crop? Not me, that is, until I discovered sweetberry honeysuckle, Lonicera caerulea, when visiting nurseries in Eastern Europe. Also known as the blue or edible honeysuckle, this little-known deciduous shrub is native to the colder, northern regions of Europe, Asia and even North America. Finding cultivated varieties in the former Eastern Bloc was not a total surprise: these countries had limited access to citrus and vitamin C during the Cold War, and as a result, they selected, bred, and developed a range of hardy fruit with high vitamin content. Mostly unfamiliar to Westerners, they grew and consumed berries such as Aronia (choke berry), Hippophae, (sea berry) and our newest discovery Lonicera caerulea, all of which are "superfruits" because of their extremely high vitamin and antioxidant content.

Lonicera caerulea produces edible fruit that looks like an elongated blueberry. 

After leaning about Lonicera caerulea and its potential, we set out to acquire as many cultivars as possible. We discovered One Green World, a small mail order nursery that offered an array of unusual fruit plants including Lonicera, which they marketed under the name "honey berries." I also met Dr. Bob Bors from the University of Saskatchewan who had an edible Lonicera breeding program, and we acquired his selections too. We purchased dried fruit, juice and jam, all of which were incredibly delicious, with a flavor best described as a tangy combination of raspberry, blueberry and raisins. Still later on a trip to Hokkaido, Japan, we were served ice cream with a haskap sauce (a type of Lonicera caerulea) that was pretty much the best food that has ever hit my taste buds. 

Haskap sauce on ice cream

It was clear that this little known honeysuckle shrub had incredible potential. First off, honeysuckles are very easy to grow. Anyone can grow this shrub. Unlike blueberry plants, it does not require any special soil or pH to grow successfully. Unlike grapes, the fruit skin dissolves in your mouth unnoticed. The fruit ripens in early summer, about the same time as strawberries, but is easy to pick without bending over. Unlike blackberries and raspberries, the plants have no thorns, and the seeds are so small you don't even notice them. On the downside, honeysuckle fruit is typically too soft to ship fresh to supermarkets, and the yields are not as high as you get with commercial blueberry crops. Until recently, the fruit also had a high degree of tartness, making it best reserved for sauces, jams, juices and drying, as opposed to eating fresh. The tartness can be largely eliminated if you understand how to identify ripe fruit: just because the fruit turns blue does not mean it's time to pick it. The fruit is ripe if you can easily remove it from the stem without tugging. If there is resistance, wait until it falls easily into your hand, otherwise you will be very disappointed with the taste.  

There is also a wide range of bitterness and sweetness depending upon the cultivar you grow. The vast majority of the Eastern European cultivars we have tasted tend to be on bitter side and are best suited for processing. Most of these cultivars are derived from Lonicera caerulea var. edulis, Lonicera caerulea var. villosa,  Lonicera caerulea var. pallasii, and Lonicera caerulea var. kamschatica. People in Eastern Europe typically call all these plants and their fruit kamschatica, zhimolost or zimolez. The vast majority of plants we initially acquired were of Eastern European origin.
                

Framtosel Krekci standing next to his new edible honeysuckle plant.  

What got us really excited about edible honeysuckle was a trip we made to the Czech Republic where we met Framtosel Krekci, a nurseryman and plant breeder who developed a new selection called Sugar Mountain® Blue. Skeptical, yet eager try a new selection, we sampled his fruit and discovered it was the sweetest we had ever tasted. We were so delighted, we worked over his hedge until every single berry was gone. Not only was the fruit sweet, it was also very large. While the typical fruit size ranges from 12 to 15mm in length, his variety had fruit in the 18 to 20mm range.    
   

Sugar Mountain Blue

My excitement and appreciation for edible honeysuckle reached new levels when I got a phone call from Dr. Maxine Thompson, a retired fruit breeder from Oregon State University. Maxine had been breeding edible honeysuckle for years, but had been working strictly with Japanese haskap, Lonicera caerulea var. emphyllocalyx, which is native to Hokkaido, Japan's northernmost island. The advantage of pure Japanese haskap is that the fruit is larger and the plants bloom later. The flowers appear as much as four to six weeks later than Eastern European varieties, making them less susceptible to frost damage, more attractive to pollinators, and better suited to warmer climates. Maxine's extensive fruit breeding experience had paid dividends when it came to haskap: her breeding lines boasted substantial improvements in both fruit size and yields. She takes detailed data, such as brix counts, so that she can maximize sweetness and other desirable attributes. Her haskap breeding program was clearly light years ahead of all others.    
         

Dr. Maxine Thompson 

Yezberry™ Maxie haskaps are nearly the size and shape of olives

After multiple visits to Maxine's breeding plot and sampling dozens of selections, we chose four of the sweetest and largest fruited plants and named them Yezberry™ haskaps. Yezberry™ refers to the island of Hokkaido, which was once called Yez or Yezo Island. It was very important to Maxine that we distinguish her breeding lines as pure haskap (Lonicera caerulea var. emphyllocalyx) originating from Hokkaido because of their unique qualities, and because, according to Maxine, growers were misleadingly selling Eastern European varieties as haskaps, which they are not.  

Thus far we have introduced four of her haskaps in the Yezberry™ Series™ . The first two are noted for their size and yield and are excellent for commercial and you pick growers Yezberry Maxie™  has the largest fruit yet: its berries are olive shaped, with very good sweetness and flavor. Yezberry Solo has large, plump fruit with very good sweetness and flavor, superior yields, and it is apomictic, meaning it will make fruit without cross pollination from another variety. Though Yezberry™ Solo™ does not require a pollinator to get fruit, you will get larger fruit and higher yields if you grow another Yezberry™ haskap in close proximity. The other two Yezberry Sugar Pie and Honey Bunch are selected for smaller more manageable plants and higher sugar content so are good for eating fresh so are perfect for you pick and home garden use.         

Yezberry™ Maxie and Yezberry Solo Japanese haskaps

The future for edible honeysuckle is bright. It is very cold hardy and easy to grow. The fruit has higher levels of vitamins C, A, and E than an orange, and three times the antioxidant level of blackberries. New breeding and the introduction of new haskap cultivars have brought us better tasting, sweeter and larger berries and plants with wider adaptability and higher yields. It is the perfect berry plant for growers selling u-pick or at local farmers markets. Best of all, it's just good fun to grow fresh, tasty fruit at home that does not require special care, soil amendments or pesticides. So hopefully, in the near future, when you think about honeysuckle, you'll think about how great it would be to mix some in your yogurt or put them on top of your vanilla ice cream. That's what I'm thinking. Yum.   

Sugar Pie is the sweetest haskap with a Brix of 15.6

Honey Bunch is a compact plant with sweet fruit

	Maxie	Solo	Honey Bunch	Sugar Pie
Plant Habit	Upright	Upright	Spreading	Spreading & upright
Plant Height meters	2	1.75	1.2	1.3
Plant Width meters	1.4	1.25	1	1.2
Growth rate	Very Vigorous	Very vigorous	Moderate -Low	Moderate -Low
Days to Harvest	64	70	63	62
Harvest Date in OR	11-Jun	21-Jun	13-Jun	10-Jun
Fruit length cm	2.3	2.2	2.2	2.3
Fruit width cm	1.6	1.6	1.6	1.6
Brix (sugar level)*	12	14.4	13.7	15.6
Fruit Wt grams - avg	2	1.8	1.6	1.8
Yield / bush kg - avg	3.5	3.5	2.2	2.8
Weeks storage 33-35oF	4	4	4	4
Dry Weight mg / 100 fruit	158	168	176	157
Market use	Commercial	Commercial	Home	Home
	Fresh	Fresh	Fresh	Fresh
	Frozen	Frozen	Frozen	Frozen
	Processed	Processed	Processed	Processed
			Dried	Dried
Pre Havest drop	Insignificant	Insignificant	Insignificant	Insignificant
Fruit Bleeding	none	none	none	none
Pollinator	Any Yezberry	Any Yezberry	Any Yezberry	Any Yezberry
Notes	Largest Fruit	Self fertile	sweet and compact	Sweetest Yezberry
	Very High Yield

Updated May 29, 2020