Hazelnut (Theta)
Corylus avellana 'Theta'
A breakthrough variety bred at Oregon State University, Theta represents the future of hazelnut growing with complete immunity to Eastern Filbert Blight. This disease-resistant variety produces medium-sized nuts with excellent flavor and kernel quality, making it perfect for regions where traditional hazelnuts struggle. Theta opens up hazelnut growing to gardeners in previously unsuitable areas while delivering reliable, heavy crops.
Harvest
120-150d
Days to harvest
Sun
Full sun
Zones
4–8
USDA hardiness
Height
12-20 feet
Planting Timeline
Showing dates for Hazelnut (Theta) in USDA Zone 7
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Hazelnut (Theta) · Zones 4–8
Growing Details
Zone-by-Zone Planting Calendar
Complete Growing Guide
Soil: High Organic Matter, Loam (Silt), Shallow Rocky. Soil pH: Alkaline (>8.0), Neutral (6.0-8.0). Drainage: Good Drainage, Moist. Height: 12 ft. 0 in. - 20 ft. 0 in.. Spread: 8 ft. 0 in. - 15 ft. 0 in.. Spacing: 6-feet-12 feet. Maintenance: Low. Propagation: Layering, Root Cutting, Seed. Regions: Coastal, Mountains, Piedmont.
Harvesting
The fruit, in the form of a nut, is enclosed by a short leafy involucre, or husk. They appear in clusters of 1 to 5 and are released from the husk in late summer when the nut has ripened. The rounded nuts are about 1" in diameter.
Color: Brown/Copper, Gold/Yellow. Type: Nut. Length: 1-3 inches. Width: 1-3 inches.
Garden value: Edible, Showy
Harvest time: Fall, Summer
Bloom time: Spring
Edibility: Hazelnuts (cobnuts) are edible, and this plant is used in the production of these nuts.
History & Origin
Origin: Europe and Western Asia
Advantages
- +Attracts: Songbirds
- +Wildlife value: Birds, squirrels, and field mice often eat the nuts. Bees are attracted to the pollen.
- +Edible: Hazelnuts (cobnuts) are edible, and this plant is used in the production of these nuts.
- +Low maintenance
Companion Plants
Plant Together
Comfrey
Deep taproot brings nutrients to surface, excellent mulch and compost material
Clover
Fixes nitrogen in soil, provides ground cover and prevents weeds
Chives
Repels aphids and other pests, improves soil health
Nasturtium
Acts as trap crop for aphids and cucumber beetles, deters ants
Elderberry
Compatible growth habits, attracts beneficial insects, similar soil preferences
Currants
Share similar soil and water needs, do not compete for nutrients
Yarrow
Attracts beneficial insects, improves soil structure and nutrient availability
Daffodils
Repels rodents that may damage nuts, blooms before leaf out
Keep Apart
Black Walnut
Produces juglone which is toxic to hazelnuts and inhibits growth
Pine Trees
Acidifies soil excessively, competes for water and nutrients
Grass Lawn
Competes heavily for water and nutrients, inhibits root development
Nutrition Facts
Per 100g serving. % Daily Value based on 2,000 calorie diet. Source: USDA FoodData Central (FDC #2515375)
Pests & Disease Resistance
Resistance
Complete immunity to Eastern Filbert Blight
Common Pests
Filbert aphid, mites, filbert weevil
Diseases
Generally disease resistant, bacterial blight possible