Corylus avellana “Theta” seeds (Theta Hazelnut)


Coming soon

Highly resistant to Eastern Filbert Blight. Theta is a good pollinizer.


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We can only offer seed to our Canadian customers only.

Seed is from the entirely EFB resistant “Theta” from the OSU’s breeding program to create new cultivars to replace those devastated by Eastern filbert blight. “Theta” is a very good pollinator with both S-loci alleles (5, 15) are expressed in the pollen a trait it inherited from its “Delta” parent.

Not self fertile. Incompatibility alleles 5 & 15 . The trees are small and upright. Nut size is similar to Yamhill.

Only three OSU hazelnuts are in this tiny grove.  Theta sits on the north position to Jefferson (1, 3) with Jefferson between it and Eta (11, 16) another good pollinator.  All three possess the dominant “Gasaway” gene responsible for EFB resistance in the OSU breeding program.

Years of research, thousands of these crosses were grown and evaluated for health, productivity, nut quality, and EFB resistance. Inferior trees were removed. Only the best remained in the program. Cell culture made mass production for export outside the OSU possible.

For more information on this fascinating hazelnut:

For the nerdy deep dive:

  • Seed Count: 10-12
  • Collection Date: Oct 2022
  • Maternal incompatibility alleles: 5 & 15
  • Hardiness Zone: 5-9
  • Height and Width: 3m x  3m
  • Preferred sites: full-semi sun; well draining moist garden soils
  • Germination test type: hand sort-smash
  • Family: Betulaceae

How to germinate Corylus seeds:

Soak in very warm water 24 hours with a couple of warm water changes just to keep the temperature up. If you are able to submerge them its best. Many tiny bubbles will indicate air/water displacement as seed soaks up.  Place soaked up nuts in a resealable baggie containing screened fine bark mulch or similar. Cold stratify for 3 months. Give gentle warmth once cold stratification cycle is over.  Keep an eye on the nuts as they can sprout rather quickly and it’s best to transplant them when the root is no longer than 2-4 cm. I prefer growing them in a communal pot to save space and to protect them from raiding rodents.  Provide strong indirect light and warmth.  If any do start sprouting while in cold stratification it’s perfectly okay to transplant them, just make sure they don’t freeze as this messes up their growing mojo.  EFB resistant.

Additional information

Weight 15 g