Cultivars for Ontario Growers updated July, 2019

Cultivars suited for zones 6-8

'Yamhill' is a main production cultivar. It is an Oregon State University introduction, accepted by Ferrero. The tree is relatively hardy and a strong grower. The tree is blight and bud mite resistant. The nut is medium size, round and well filled. Nuts start dropping early to mid-September.

Alleles are 8 and 26. 'Yamhill' will pollinize all our selections with known alleles.
Female bloom is hardy for zone 6b-8.
Male catkins are hardy for zone 7-8.

'Jefferson' is a main production cultivar in Oregon. It is an Oregon State University introduction accepted by Ferrero. The tree is relatively hardy and a strong grower. The tree has weak blight resistance and good bud mite resistance in Ontario. Pruning and sprays will be needed to control filbert blight. The nut is large size, round and well filled. The nuts start dropping early October. It is considered a replacement for Barcelona the old dominate cultivar.

Alleles are 1 and 3. 'Jefferson' is compatible with all our selections except 'Slate' and 'Chelsea'.
Female bloom is hardy for climate zones 6b-8.
Pollen shed is late season. Male catkins are hardy for zone 7-8.

'Gamma' was selected in Oregon as a pollinizer accepted by Ferrero. It is moderately blight resistant with good bud mite resistance. It is a good producer of medium size, round, well filled nuts. Nuts start dropping early to mid-September. 'Gamma' has shown to be the best trial cultivar from Oregon in our test orchard for hardiness and production. We consider it to be a good main crop cultivar for Ontario.

Alleles are 2 and 10. 'Gamma' will pollinize all our cultivars with known alleles except 'Joanne' and 'Tonda di Gifoni'.
Female bloom is hardy for climate zones 6b-8.
Pollen shed is mid-season. Catkins are hardy for zones 6b-8.

'Slate'^TM is a very productive compact tree and some years a good pollinizer. It is the product of a major breeding program in zone 6a and has proven to be highly blight resistant but not bud mite resistant. It is an American x European hazel hybrid. Even with bud mite, the tree is still very productive. The nut is large, slightly oval in shape and most drop out of the husk when ripe. The nuts start dropping mid-October.

Alleles are 1 and 23. 'Slate' will pollinize 'Yamhill', 'Gene', 'Alex', 'Carmela', 'Aldara' and others that do not share the same alleles.
We recommend it as a main producing cultivar in climate zones 6-8.
Pollen shed is late season. Catkins are hardy for zones 7-8.

'Gene'^TM is our main pollinizer and is also a prolific nut producer. It is a vigorous, spreading, highly blight resistant hybrid tree from a large breeding program in zone 6a. It is an American x European hazel hybrid. The nut is medium to large size, and slightly oval in shape. Most nuts drop out of the husk when ripe. The nuts start dropping mid-October.

Alleles are 15 and 23. 'Gene' will pollinize all our selections except 'Dawn'.
We recommend it both as a pollinizer and as a main crop tree for zones 6-8. Pollen shed is mid-season.

‘Cheryl’™ is a selection from a large breeding project in zone 6a. It is an American x European hybrid with good blight resistance. It is not bud mite resistant, though still very productive. The tree has medium to large slightly oval attractive nuts. Most nuts drop out of the husk when ripe. The nuts start dropping early to mid-October. The tree is upright but wide spreading. 'Cheryl' would be a good main crop orchard tree. Nuts begin dropping mid-October.

The alleles are 10 and 12 with pollen expressed in both alleles. It would be a good pollen match for all cultivars in our list except for 'Norfolk' and 'Gamma'.
'Cheryl' is a late season pollinizer. Male catkins are hardy for zone 6-8.

‘Linda’™ is an American x European hazel hybrid selection like Cheryl above. Nut size and tree characteristics are similar to 'Cheryl' also. It too is blight resistant, and bud mite susceptible. 'Linda' would be a good main crop producing tree. Nuts begin dropping mid-October.

The alleles are 14 and 23 with pollen expressed in 14. It would be a suitable pollen match for all our selections listed here except for some of our northern cultivars including 'Frank', 'Marion', 'Joanne' and 'Julia'.
'Linda' is a late season pollinizer. Male catkins are hardy for zones 6-8.

'Norfolk'^® is selected by Martin Hodgson. It is a large oval nut and hardy in the Simcoe Experiment Station planting. It is modest bearing, so is recommended as a pollinizer, since it produces an abundance of pollen. Nut quality is good.

Alleles are 12 and 25. 'Norfolk' will pollinize all our selections except 'Marion'. It can pollinize 'Carmela', but 'Carmela' will not pollinize 'Norfolk'.
Female bloom is hardy for climate zones 6-8.
Pollen shed is early to mid-season. Male catkins are hardy for zones 6-8.

'Chelsea'^® is selected by Martin Hodgson. It is a large oval nut and hardy in the Simcoe Experiment Station planting. It is recommended as a pollinizer as it produces an abundance of pollen and has good quality nut. It is a modest bearing selection.

Alleles are 1 and 20. 'Chelsea' will pollinize all selections with known alleles except 'Jefferson', and 'Slate'.
Female bloom is hardy for climate zones 6-8.

'Alex'™ is a selection by Ernie Grimo. It is a medium size, oval, well filled nut. It is a seedling of ‘Faroka’, a Turkish tree hazel hybrid. 'Alex' is a good annual bearing, strong upright tree. It has potential as a pollinizer. It is bud mite and blight resistant. It shows no blight in Rutgers University experimental orchards. The nuts begin to drop mid to late September.

Alleles have not been identified yet, but PEI hand crosses show it will pollinize 'Jefferson', 'Gene', 'Slate' and probably most of the other selections.
The female bloom is hardy for climate zones 6-8.
Alex is a mid-season pollinizer. Male catkins are hardy for zones 6-8.

‘Matt’™ is a selection by Ernie Grimo and a sister tree to Alex. It is a medium to large size, oval shaped, well filled good quality nut. Matt is a seedling of ‘Faroka’, a Turkish tree hazel hybrid. 'Matt' is a biennial bearing selection with good upright form. It has potential as a pollinizer. It is blight and bud mite resistant. Nuts begin dropping mid to late September.

It has alleles 11 and 13, but pollen expression has not been identified. Only 'Julia' would not be a suitable match of all selections.
'Matt' is an early season pollinizer. Male catkins are hardy for zones 6-8.

'Carmela'™ is a selection by Ernie Grimo. It is an extra-large, oval shaped, well filled nut. It is a biennial bearing tree with heavy and lighter crops on a 2-3 year cycle. The nuts start dropping mid to late October. It is a good pollinizer for zone 6b-8 and because of the large size, it can be screened out to keep varieties separate in the harvest. In 40 or more year it has never had blight. It shows no blight in Rutgers University experimental orchards.

'Carmela' has alleles 23 and 25. It is a suitable pollinizer for all our selections except for 'Norfolk' and 'Aldara'.
Female bloom is hardy for climate zones 6-8.
Pollen shed is late season. Male catkins are hardy for zones 6-8.

‘NORTHERN’ CULTIVARS – SUITED FOR COLDER CLIMATE zones 4 or 5-8

‘Dermis’™ is a selection by Ernie Grimo. It is a ‘Skinner’ seedling. Mr. Skinner was a Manitoba breeder crossing his native American hazel with European or European hybrids. One selected tree was named for him. 'Dermis' is a very productive tree with good blight resistance, but is bud mite susceptible. The nuts are medium size, well filled and nearly round with a slightly harder shell than our other selections. It is a larger wide spreading tree unlike its parent or other ‘northern’ hazels. Dermis would fit in well wherever it is planted. The nuts begin dropping in mid-October.

The alleles have not been identified yet, but it is known to be compatible with 'Gamma', 'Linda', 'Cheryl', 'Gene', 'Frank', 'Marion' and 'Dawn'.
Female bloom is hardy for zone 5-8, possibly zone 4.
pollen shed is mid and late season making it an outstanding pollinizer. Male catkins are hardy for zone 5-8.

'Aldara'™ is a selection by Ernie Grimo. It is an "Asian/Quebec source" tree growing to about 3-4 m tall and spreading about 3 m wide. It is very productive and blight resistant. The nuts are medium size, round and begin to drop late August. We consider it a good selection for a main orchard tree for a zone 4-5 orchard.

Alleles are 25 and 27. We do not know which allele is expressed in the pollen, so we need to avoid matching it with all cultivars that share either allele. It is a suitable pollinizer for most of our main crop cultivars.
Suited for climate zones 4-8 for both female flowers and male catkins.
Pollen shed covers mid to late season.

'Andrew'™ is a selection by Ernie Grimo. It is an "Asian/Quebec source" tree growing to about 3-4 m tall and spreading about 3 m. It is moderately productive, blight resistant, but not bud mite resistant. We consider it suitable as a pollinizer. The nuts are medium size round and begin dropping mid to late August.

Only allele 27 has been identified, but PEI hand crosses show it will pollinate 'Yamhill', 'Gene', 'Slate', 'Carmela' and 'Matt'.
Suited for climate zones 4-8.
It is a mid-season pollinizer.

‘Dawn’™is a selection by Ernie Grimo planted in 2008. It is a sister tree to Andrew and Aldara from the ‘Asian/Quebec’ source. This medium size tree is one of our most productive selections even though it is affected by bud mite. It has good blight resistance. The nuts are slightly smaller than 'Aldara' in size, round and well filled. The nuts begin dropping mid to late September.

Alleles are 15 and 27 with pollen expressed in 15. It is not compatible with Gene and possibly 'Aldara', but it is compatible with all other listed selections.
'Dawn' spans early and mid-season for pollinizing. Male catkins should be hardy for zones 4-8.
It is in tissue culture and quantities of trees will be available in 2022 at the earliest.

‘Northern Blais’™ is likely an Asian/Quebec source tree, planted in our test orchard in 2012. It was the best seedling sold to Jacques Blais in Joly, Quebec, zone 4b. The medium size tree had a good crop every year even though it was affected by bud mite. It has good filbert blight resistance. The nuts are medium size, round and well filled, dropping in late August to early September.

The alleles are 8 and 25, so it will match with any hazelnut that does not share either of the same alleles.
Northern Blais is a late season pollinizer. Male catkins should be hardy for zones 4-8.

‘Nathan' is a newly named selection planted in our test orchard in 2005. Our most recent 3-year evaluation summary places it with our most productive Asian/Quebec source trees. This medium size tree has nuts that are medium size, round and well filled. The nuts start dropping by early September. We hope to have some trees available for 2023.

The alleles are 8 and 11, so it will match with any hazelnut that does not share either of the same alleles.
'Nathan' is an early pollen source. It should be suitable as a pollinizer for zones 4-8.

‘Marion’™ is a medium size, Saskatchewan source tree, planted in 2001. The parent tree of the Saskatchewan trees was a hybrid cross of a Saskatchewan American hazel (zone 3) x European hybrid (zone 6). Our Saskatchewan source trees are all from this cross. 'Marion' has good blight resistance. It is bud mite susceptible but still produces good crops. The nuts are medium size, round with good nut filling. Nuts begin dropping late August to early September.

'Marion' has alleles 14 and 25 with 14 expressed in the pollen. It has a long female receptive period to ensure a crop. Care needs to be taken that is matched with suitable pollinizers. It is not compatible with 'Carmela', or sister trees 'Julia' and 'Joanne', or possibly 'Frank' and 'Aldara'.
It is a late season pollinizer. Male catkins should be hardy for zones 4-8.

‘Frank’™ is a medium size, Saskatchewan source tree, planted in 2001. 'Frank' has good blight resistance. It is bud mite susceptible but still produces good crops. The nuts are medium size, round with good nut filling. Nuts start dropping late August to early September.

14 is the only allele identified so far for 'Frank'. It will need to be matched with any selection that does not have this allele.
'Frank' is a late season pollinizer with a long receptive period. Male catkins should be hardy for zones 4-8.

‘Joanne’™ is the smallest size, Saskatchewan source tree, planted in 2001. 'Joanne' has good blight resistance in Ontario. It is bud mite susceptible but still produces good crops. The nuts are medium size, round with good nut filling. Nuts begin dropping late August to early September.

'Joanne' has alleles 2 and 14 with pollen expressed in 14. From our list of trees, it is not compatible with 'Gamma', 'Linda', 'Marion', 'Julia' and probably 'Frank' and 'Kiara'.
'Joanne' is late season pollinizer. Male catkins should be hardy for zones 4-8.

‘Julia’™ is a medium size, Saskatchewan source tree, planted in 2001. It is blight susceptible and bud mite susceptible. Pruning and spraying will be needed to keep these problems under control. Even with these issues, Julia still produces heavier crops than other northern source trees except for ‘Kiara’. We only recommend it for trial purposes. The nuts are large size, round and well filled. Nuts begin dropping mid to late September.

Julia has alleles 11 and 14 with 14 expressed in the pollen. From our list of trees, it is not compatible with Linda, Marion, Joanne and possibly Frank or Kiara.
Julia is a mid-season pollinizer. Male catkins should be hardy for zones 4-8.

‘Kiara’™ is a small to medium size, Saskatchewan source tree, planted in 2001. Our most recent 3-year evaluation summary places it with our most productive trees. It has been our best producer of this tree source. It is blight resistant but is susceptible to bud mite. The nuts are medium size, round and well filled. Nuts start dropping early to mid October. Since it is a recent introduction, trees will not be available until 2022 at the earliest.

'Kiara' has alleles 14 and 23, so it should not be matched with hazelnut trees that share the same alleles
'Kiara' would be a good pollinizer since it sheds pollen over the mid to late season. Male catkins should be hardy for zones 4-8.

Alleles Explained– An allele is one of a pair of genes that appear at a particular location on the chromosome that controls breeding compatibility. Hazelnut alleles are numbered to identify them. All hazelnuts carry two alleles but they are blocked from pollinizing themselves. To simplify, for hazelnuts to cross pollinize, the numbers from one parent must be different from the allele numbers in the other parent. For example, 'Gamma' has alleles 2 & 10, 'Yamhill' has alleles 8 & 26, and therefore they are compatible both ways. This means that 'Gamma' can pollinize 'Yamhill' and 'Yamhill' can pollinize 'Gamma'.

Underlined allele numbers indicate that male pollen is expressed by that number. Nuts will not be set when either of the alleles in the female flower matches this expressed alleles in the pollen. For example, 'Jefferson' has alleles 1 & 3. 'Slate' has alleles 1 & 23. 'Slate' pollen is expressed in allele 1 and not in allele 23, but since there is a 1 in the female flower of 'Jefferson', they are incompatible. Vice versa, 'Jefferson' pollen is expressed in allele 1 but it can’t pollinize 'Slate' because of the female allele 1.

Here is an exception to the above. 'Slate' has alleles 1 & 23. 'Gene' has alleles 15 & 23. Since 'Slate' has the expressed pollen allele 1 and 23 is not expressed, 'Slate' can pollinize 'Gene'. Alternatively, 'Gene' has allele15 expressed in the pollen and 23 is not expressed, so it can pollinize 'Slate'.

Pollinizer studies by the PEI Soil and Crop Association have identified some of the cultivars that will cross with each other even though the alleles have not been identified yet. This study is available on request.