A Little Hazelnut History

Do hazelnuts grow in North Dakota? You may be surprised learn that hazelnuts are a native shrub that grows naturally in both North Dakota and Minnesota. They might even be growing near you.
I read that hazelnuts were some of the first plants to colonize this area after the glaciers melted about 10,000 years ago. I was a little skeptical at first, but after finding hazelnuts in so many places in North Dakota, and the fact that each plant had such different characteristics. Some were very short about 3 feet high while others were over 15 feet high and the husk which covers the nut on some are a smooth leaf like structure and others have a very fat, juicy husk with little hairs.  Some are growing in heavy high ph soils, some growing in sandy dry soil, and some growing in low ph bogs with blueberries. For the same plant to occupy so many different types of locations it must have taken many years to adapt to all these different types of ecosystems.
Officially there are two species of hazels native to this area, the American hazelnut (Corylus Americana) and beaked hazelnut (Corylus cornuta).

This is one type of American hazelnut that I’ve found in the northern part of our state.
It was about 4 feet high and had a leafy type of husk with 2 or 3 nuts in each cluster.
This plant is a multi-stem suckering shrub and the stems are usually less then 1/2 inch thick.
This one plant can take over quite a large area, and is probably something that you would not want in a small garden.

The small green cylindrical columns hanging from this American hazelnut branch are catkins (male flowers) that develops on the plant in the late summer and will open the next spring to release pollen for the female flowers on the neighboring plants. Hazelnuts are not self pollinating, so two or more plants are needed for a good nut crop.
On this plant a single catkins hangs underneath each leaf node. I’ve found most wild hazels in North Dakota have this characteristic of single catkins, which is unusual because most other hazelnut varieties have multiple catkins hanging from one leaf node.

This is a beaked hazelnut is usually found as a understory shrub located around some lakes in low ph sandy or loamy soils. The nuts have a long hairy beak like husk, which can irritate your hands when picked. They usually are in cluster of 2 but I’ve also seen them in clusters of 4. The nuts are small with a thin shell with a fair taste.
The leaves of both types of hazelnuts are very similar being alternate, simple, with double toothed margins. As you can see the best way to identify which type is by the husk or the catkins. 
I’ve tried growing these beaked hazels in heavy high ph soils in this area of the Sheyenne River and have only managed to grow just the one shown above. 
These are the dual catkins of the beaked hazel, and are always pointing in an upwards direction.
This makes identifying a beaked hazelnut during the late summer, fall, and winter very easy.
The female flowers of both hazels are really hard to tell apart, except for the fact that beaked hazelnut blooms a week later then the American hazelnut. 
The big differences of the American hazelnuts have really fascinated me. This plant was growing in an open area in the Sheyenne Grasslands south of Leonard ND and is over 15 feet tall and with stems that are over 2 inches thick.
The fruit of this hazel that grows in this open area has a fat and juicy husk around a thick shelled nut.

I found hazels growing south of Valley City in small state park with a creek. The trees in this area are mostly oak. Some of the under story shrubs are choke cherries and hazelnuts with buckthorn taking over parts of the under story. 
Here I’m investigating the hazelnuts on the edge of this wooded area in the park. Most of these plants were about 5 feet tall and produced large amount of nuts every year. I assume that the squirrels concentrated on the large amount of acorns that ripen earlier then the later thicker shelled hazelnuts.

These are the hazelnut from  Little Yellowstone Park.
The husk on these are almost perfectly round, and juicy.
It has a medium sized nut with a thicker shell then most American hazelnuts, and the taste isn’t too bitter.

These hazelnuts growing in Oregon are European hazelnuts (Corylus avellana) and would be multi-stem shrubs but they remove the suckers and are trained to grow as small trees. 
There are also hazelnuts that grow as a large sized tree called a Turkish tree hazelnut(Corylus colurna). These 40 to 50 foot trees produces low numbers of small nuts and takes 7 to 10 years to produce nuts.
This European type of hazelnuts is one of the larger nuts that drops out of the open husk when ripe. They are then swept up off the ground, washed, and processed. 
These are the catkins from a European hazelnut. 
These type of hazelnuts always have multiple green catkins hanging from one leaf node.
Easter Filbert Blight (EFB) is a fungi that affects most European hazelnuts which have little or no resistance and usually succumb to this disease in 2 or 3 years.
Most American hazelnuts are resistant but will carry EFB.  There are now a few universities and other groups crossing hazelnuts from around the world to find a resistant verities of plants with these same large nuts.
Almost all of these European hazelnuts are not hardy enough to grow in North Dakota.
I started an orchard near Horace, ND in 1978 with some native American hazelnuts from Northern Minnesota and later added collections from elsewhere including the Sheyenne Grasslands. I then purchased some hazelnuts with the European back ground including some three way hybrids. Almost  all of these did not make it through our winters, but a few did and with that genetic diversity I began picking and growing out nuts with a larger size, thinner shell, and the better flavor like that of the European filberts, but with the cold hardiness of the American hazelnuts.
I also began picking other traits such a non-suckering, more of a tree like structure, and a plant in which the nuts could be easily removed from the husk.
I also found that some of these new varieties were not resistant to Easter Filbert Blight and I lost some of my best plants. Now EFB resistance has become another trait I’ll have to consider.
The hazelnut in the picture above is one of my plants with more of a tree like structure, but does produce one or two suckers every year. Even more important is that it’s resistant to EFB.
My latest projects are hand pollinating and cloning some of my best plants.
The hazels in this picture are all either hand pollinated or clones, and this spring almost all will produce nuts for the first time. 
This is not a hazelnut but the nut of a buckeye. 
I thought you might what to see something another then hazelnuts

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