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close up picture of a lot of hazelnuts in a pile close up picture of a lot of hazelnuts in a pile

Hazelnuts

Corylus avellana

hazelnuts in a hand
Image by Oregon AITC on Flickr

Importance of Hazelnuts to Oregon

There are so many hazelnuts grown in Oregon that they are the state nut. The nuts are grown by more than 1,300 farms in Oregon. Those farms grow 100% of the hazelnuts in the United States. The countries Italy and Turkey are the only places that grow more hazelnuts than Oregon. In 2020, Oregon grew 63,000 tons of nuts, which were worth 132 million dollars. That made them the 10th most valuable agricultural commodity in the state that year.1

History of Hazelnuts

Some people call hazelnuts filberts. They grow wild in parts of Europe and Asia. They have been eaten since prehistoric times. Burned hazelnut shells have been found that are from 8000-2700 BCE. They were found in Sweden, Denmark, and Germany. A Chinese book from 2838 BCE says that hazelnuts were a sacred food in China. 

black and white picture of a girl harvesting hazelnuts in an orchard
1910, Oregon Historical Society Research Library, Digital Collections, OrgLot78_B5F5_018

Sam Strictland planted the first hazelnut tree in Oregon in 1858. It was in Scottsburg. A man named Felix Gillet was important to Oregon hazelnuts. He brought new varieties to the state. George Dorris started the first hazelnut orchard in Oregon. He planted 50 Barcelona trees in 1903. The trees were bought from Felix Gillet. His orchard is in Springfield. It now has 9,250 trees.2  

Willamette Hazelnut Orchard, 2017, Image by Bonnie Moreland on Flickr

George Dorris also had a nursery and sold trees to farmers. More than half the hazelnuts in Oregon today might be from that nursery stock3.

Hazelnut Varieties

Farmers in Oregon plant many different types of hazelnut trees. These types are called varieties. Oregon State University works to create new hazelnut varieties that grow well in the Oregon climate and are resistant to Eastern filbert blight, a disease that has hurt many orchards in the state. Some varieties are pollinizers. Every orchard needs a certain amount of pollinizers. Many varieties are named after important people or places in Oregon history.
closeup picture of a barcelona hazelnut

Barcelona

Barcelona is the most common variety grown in Oregon. More than 60% of the hazelnut acres in Oregon are Barcelona. They have a strong flavor and round nut that processors prefer. Because it has been grown for so long, it is the variety that others are compared to. A problem with Barcelona is that they are more likely to get Eastern filbert blight. 

closeup picture of jefferson hazelnuts

Jefferson

Jefferson trees are resistant to Eastern filbert blight and are a common variety. The nut they produce is larger than many others. The nuts are harvested in early to mid-October. Nuts from Jefferson trees are good for many different uses.4

closeup picture of yamhill hazelnuts

Yamhill

Yamhill hazelnuts are harvested in early October. They are also resistant to Eastern filbert blight. This variety produces many nuts. They are a smaller tree, compared to varieties like Barcelona.5

closeup picture of york hazelnuts

York

York is a pollinizer variety and makes a lot of pollen. It is resistant to Eastern filbert blight. This makes it a good variety to plant with other tree varieties. It is also resistant to bud mite, which can damage hazelnuts. York nuts are harvested in early October.6

Life Cycle of a Hazelnut

Hazelnuts naturally grow like a bush or shrub. In Oregon, farmers grow hazelnuts as a tree, with one trunk. This means that farmers have to make them grow into a tree by pruning them every year.  

Hazelnut orchards are usually planted in early winter. The trees are planted in straight rows with enough space to grow into large trees. The trees can grow up to 40 feet tall. Sometimes farmers will plant them closer together and then remove some trees when they get too big. 

After they are planted, it will be close to four years before nuts are harvested. The trees don’t grow very many nuts the first few years of life. Healthy hazelnut trees can grow nuts for 40-50 years.

Bloom and Pollination

Hazelnuts are monoecious and have male and female flowers on the same tree. The male flowers on a hazelnut are long, yellow catkins. The female hazelnut flowers are tiny red, purple flowers. Hazelnut trees bloom and pollinate in the late winter before the leaves emerge. Wind carries the pollen from male catkins to the flowers on other trees. The nuts won’t start to grow until late spring. Then they will grow quickly until harvest. The nuts grow in groups called clusters. Each nut has a protective husk. The nuts mature at the end of summer. They are green while growing, but become brown by harvest time.7

Male Hazelnut Blossom

The male flowers on a hazelnut are long, yellow catkins.

Female Hazelnut Blossom

The female hazelnut flowers are tiny red, purple flowers.

closeup of unripe, green hazelnuts

Unripe Hazelnut

Each nut has a protective husk. The nuts mature at the end of summer. They are green while growing, but become brown by harvest time.

Hazelnut Harvest

Hazelnuts are harvested in September and October. Ripe nuts fall on the orchard floor. Farmers then drive a sweeper through the orchard. It sweeps the nuts into rows between the trees. After the nuts are swept, a harvester drives down the rows and picks up the nuts. Then the hazelnuts are taken to a truck. The nuts are taken from the field to a processor. They may be dried, cleaned, shelled, roasted, and more.
picture of harvester picking up hazelnuts after they were swept into the aisle
Image by OSU Extension Services Catalog
Harvester Picking Up Hazelnuts

hazelnuts in the back of a harvester after being picked up
Image by jacki-dee on Flickr
Hazelnuts After Being Picked Up By A Harvester

picture of hazelnuts on a conveyer belt and in bags
Image by Oregon AITC on Flickr
Hazelnuts Being Harvested and Processed

closeup picture of eastern filbert blight spores on a twig/branch

Eastern Filbert Blight

Eastern filbert blight is one of the main hazelnut diseases. Infected trees produce less nuts than healthy trees. Branches infected with the disease can die during the summer. Many farmers take out trees with Eastern filbert blight and plant new trees. Many new varieties are resistant to the disease. 

picture of bacterial blight spots on leaves

Bacterial Blight

Bacterial blight is the second-worst disease in Oregon hazelnuts. Years with lots of rain cause the disease to get worse. The disease can kill young trees if it gets in the trunk bark. It can kill the twigs of older trees. Less twigs and buds mean less nuts from the tree. 

closeup picture of an adult filbertworm

Filbertworm

Filbertworm is the worst insect in hazelnuts. The insects eat the nuts as they grow. This means there are less nuts to harvest. The filbertworm does the most damage during the summer. 

closeup picture of a hazelnut aphid

Aphids

The filbert aphid and hazelnut aphid both damage hazelnuts. The aphids suck juice out of the leaves. They can also leave mold on the leaves. The mold means less leaf surface for the sun to shine on. Filbert aphids have been found since 1903 in the United States. Hazelnut aphids have been found in Oregon since 2003.8

Uses for Hazelnuts

Hazelnuts can be found in candies, snack mixes, and coated in different flavorings. They can be eaten raw or roasted. Nutella is made out of hazelnuts. The nuts can be ground up and used as flour. They are also used as a topping on different foods. The nut oil can be used for cooking.Hazelnut shells can be used to make garden paths. Sometimes they are fed to animals.
Hazelnut Products

picture of chocolate covered hazelnuts
Image by Oregon Department of Agriculture on Flickr
Hazelnut Snacks

close up picture of a squirrel eating a hazelnut
Image by Светлана from Pixabay
Animal Food

Fun Facts About Hazelnuts!

  • The hazelnut became Oregon’s official State Nut in 1989
  • In 2018, Oregon grew enough hazelnuts to feed all Oregonians one serving every single day of the year – and then some!
  • June 1 is World Nutella Day
  • Chocolate is the favorite flavor people want to eat with hazelnuts9

Vocabulary Terms

The male part of hazelnut flowers.

Temperature, rain, and wind at a location over a period of years.

A product, good or service that is sold at a price.

A plant that has female and male flowers.

Plants grown in nurseries to be sold.

A tree variety that makes pollen to pollinate other trees in the orchard.

A machine used to dry and clean nuts.

Cutting off and removing branches.

Strong and able to not get infected by disease.

Related Resources and Sources


        1Oregon Department of Agriculture. “Oregon Agricultural Statistics.” October 2021. https://www.oregon.gov/ODA/shared/Documents/Publications/Administration/ORAgFactsFigures.pdf. 
        2Olsen, Jeff L. “Growing Hazelnuts in the Pacific Northwest: Introduction.” Oregon State University Extension Catalog. October 2017. https://catalog.extension.oregonstate.edu/em9072/html.
        3Oregon Hazelnuts. “Hazelnuts Fun Facts.” Accessed January 2022. https://oregonhazelnuts.org/about. 
        4———. “‘Yamhill’ Hazelnut.” Oregon State University Extension Catalog. August 2009. https://ir.library.oregonstate.edu/downloads/nk322d784.
        5———. “Hazelnut ‘York’.” Oregon State University Extension Catalog. Accessed January 2022. https://oregonstate.technologypublisher.com/tech/Hazelnut_’York’.
        6Olsen, Jeff L. “Growing Hazelnuts in the Pacific Northwest
        7Pollination and Nut Development.” Oregon State University Extension Catalog. November 2013. https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/em9074.pdf.
        8Olsen, Jeff L., Jay W. Pscheidt and Vaughn M. Walton. “Growing Hazelnuts in the Pacific Northwest: Integrated Pest Management.” Oregon State University Extension Catalog. November 2013. https://catalog.extension.oregonstate.edu/em9081/html.  
        9Oregon Hazelnuts. “CULTIVATE INNOVATION WITH OREGON HAZELNUTS.” Accessed January 2022. https://oregonhazelnuts.org/why-choose-hazelnuts/.