Artificial hybrids with intermediate features, bred solely for nut production in North America.
USDA Hardiness Zone 3-4
RHS Hardiness Rating H7
The European Corylus avellana is the hazel species which has been most extensively bred to produce heavy crops of large, thin-shelled nuts, but the species’ cultivation in North America is severely compromised by its vulnerability to the endemic fungal disease Eastern Filbert Blight (EFB). C. avellana is also less hardy than the two hazel species native to the United States and Canada.
In attempting to produce a hardy and EFB-resistant fruiting hazel, the majority of American breeders have concentrated on hybridising old European selections of Corylus avellana (and C. maxima) with C americana, which like C. avellana has short husks which can release the ripe nut; its nuts have similarly thin shells, but are smaller. The other North American hazel, C. cornuta, can be even hardier, but its nuts have thicker shells and they fall still enveloped in their long, prickly husks. These nuts do ripen earlier – a potential advantage near the West Coast where America’s hazelnut industry is largely based, and where a reliably dry August gives way to very wet autumns which can make mechanical harvesting of hazelnuts tricky.
Corylus cornuta and C. avellana are not closely related, and during their extensive researches into hazel hybridisation at Oregon State University in the late twentieth century Veli Erdogan and Shawn Mehlenbacher found this one of the hardest pairs to hybridise (Erdogan & Mehlenbacher 2000). Earlier in the century, however, Jack Gellatly in British Columbia was successful in crossing a very hardy strain of C. cornuta, which he had collected in the Peace River district of Alberta, with clones of C. avellana that he had also selected for hardiness (Gellatly 1950). Gellatly christened these hybrids ‘filazels’ and released fifteen selections of which ‘Peoka’, ‘Manoka’, ‘Fernoka’, ‘Farioka’ and ‘Myoka’ were the most successful; the last of these was still available in 2010 (Molnar 2011). (‘Farioka’ should not be confused with Gellatly’s better-known C. × colurnoides hybrid, ‘Faroka’.) Another hybrid, ‘Peace River’, is still recommended for places too cold for other fruiting hazels (Nomad Seed Project 2019).
More recently, the Badgersett Research Corporation in Minnesota has continued breeding hardy hazels by hybridising European fruting clones with both Corylus americana and C. cornuta (Badgersett Research Corporation 2023). This group of complex hybrids receives its own (brief) entry in this account, under the title Corylus Badgersett Hybrids.