The hazelnut also known as filbert or cob nut, has native species that are widespread over North America, Europe and Asia. Our native species, the beaked hazel and the American hazel are very hardy, well adapted small, 1-2 m tall, bushy plants, producing quantities of small sized thick shelled nuts. The European hazels, on the other hand, are larger plants, 3-4 m tall, with large thin shelled nuts. Though less hardy, they will grow in the milder regions of North America. They are grown commercially in Oregon northward to the Fraser Valley of British Columbia.

In Eastern North America, hazelnuts have not been commercially successful. This is largely due to a disease called eastern filbert blight, a fungus disease which invades the twigs and eventually kills the plant. The native hazels are resistant, some are even immune to this disease. The Turkish tree hazel is also resistant to eastern filbert blight. A number of breeders have crossed these species with each other, resulting in selections that are hardier than the European and resistant to the blight. The trees are intermediate in size but have the European nut size.

In recent years, eastern filbert blight has found its way to the commercial plantings of the west coast. Oregon State University scientists have been breeding hazelnuts for resistance with the intention of selecting trees with complete immunity, in time. These trees and some of the hybrid selections from the east may be suitable for commercial plantings in zone 6 regions of Ontario, near the Lower Great Lakes, including Georgian Bay.

The hazelnut hybrids tend to bloom very early, often in March, like their European parent. Though the female flower is very hardy, a cold snap during bloom can affect nut set. The catkins or male bloom are also susceptible to damage caused by freezing temperatures. Since blooming is extended over several weeks, crop failures are usually avoided. It is important as a result to have a number of different pollinators in an orchard to effectively pollinate the orchard and to overcome the periodic cold spells that usually occur in March. Pollinators can be seedlings or several grafted or layered cultivars. Hazelnuts are self infertile, so at least two different cultivars or seedling plants are needed to produce nuts.

Hazelnuts are fairly shallow rooted and do well in a range of well-drained soils from sand to clay loams. Field tiles should be used to improve the drainage and though they are somewhat drought tolerant, irrigation should be set up for long dry spells. Better nut quality and sizing of the nut will result.

Hazelnuts can be grown from seed. The blight resistant selections can produce seedlings that have 70% blight resisting offspring. Orchards established with seedlings need to be culled of the blight susceptible trees, the trees with the poor filling nuts, the small or poor quality nuts and the trees with too much bran material adhering to the kernel. New seedlings can be planted to take the place of the culls, but a better way would be to use superior replacement trees that are layered or grafted. Alternatively, layered or grafted trees can be planted from the start. This more expensive alternative will save some work down the road. Layered trees are produced by rooting the sprouts that come up around the base of a hazelnut bush. These sprouts are identical to the tree from which they come and so can be removed from the plant and started as a new tree with the exact characteristics as the parent tree. Grafted trees are best on Turkish tree hazel rootstocks. These rootstocks are generally blight resistant, hardy and relatively non-suckering.

Seedling and layered hazelnut trees will need to be suckered once or twice during the growing season. Hazels have a bush habit, that is, they produce multiple stems and annually add more sprouts from the root crown. This habit is undesirable to the orchardist as it interferes with the mechanical collection of the nuts. By training the bush to a single trunk right from the time it is planted, a tree form is established. Then it is a simple matter of spraying the young sucker sprouts annually to maintain the single trunk form.

Important Hazelnut Characteristics

1. Medium to large size nuts are most desirable. Medium round, thin shelled nuts are important to the processing trade, while the larger nuts, either round or oval are attractive for the in-shell market.
2. Eastern Filbert Blight Resistance Sprays and pruning can reduce the effect of this disease, but resistant selections are more desirable, and ultimately immune cultivars.
3. Production The orchard trees must produce good crops annually. There should be a minimum of blanks (empty nuts) and the nuts should drop clean from the husks.
4. Bud Mite Resistance. Small tight buds tend to resistant the penetration of the bud mite and so limit infection of buds by this hazelnut pest. These mites feed inside the bud and destroy shoot and flower tissues, limiting the crop. Sprays are needed to control this pest where resistance is not high.

Hazelnut Cultivars for the East

A few of the most blight resistant selections are listed here indicating some of the desirable characteristics.

Geneva - A highly blight resistant, possibly immune, hybrid selection. It is very productive and a relatively large plant. Nuts are large and well filled with a clean firm kernel. Ripens mid October. There are few blanks and it drops clean from the husk. It has moderate resistance to bud mite.

Slate - A highly blight resistant, possibly immune, hybrid selection. This is a very productive medium sized plant, producing few suckers. The nuts are large, well filled with a clean firm kernel. This selection ripens a few days ahead of Geneva. There are few blanks and it drops cleanly from the husk. It has moderate resistance to bud mite.

Grimo 208D - This is a highly blight resistant, possibly immune, seedling of Faroka. Faroka is a Turkish x European hybrid cross made by Jack Gellatly of West Bank, BC. This selection is a large, moderately productive with a tendency to biennial bearing. The nut is large, well filled with a clean kernel. The nuts ripen the last week of September and drop clean from the husk. It has good resistance to bud mite.

Grimo 186M - This is a highly blight resistant, possibly immune, seedling of Faroka, a sister tree to 208D. The tree is large and moderately productive. The nut is large, well filled with a clean kernel. The nuts ripen at the end of September and drop clean from the husk. It has good resistance to bud mite.

Skinner native hazel hybrid Mature Size

Skinner - This hybrid was selected in Manitoba. It has moderately high resistance to filbert blight. It could be kept blight free by carefully pruning out infected branches which tend to suppress the spread of the fungus. It is a productive medium sized tree. The round nuts are medium to large resembling the American native, well filled with a medium hard shell. The kernel is clean and firm. The nuts ripen the first week of October and most drop clean from the husk. It has moderate resistance to bud mite.

Grand Traverse - This is a Faroka cross made by Cecil Farris of Michigan. It has moderate blight resistance. It is productive and forms a large tree. The nut is medium in size, well filled and clean. The nuts drop clean from the husks about the last week of September. It has good resistance to bud mite.

Blue jays are a major pest in hazelnuts. They carry away the nuts as they ripen and flocks are capable of substantially reducing the crop. It takes two or more deterrents to keep them away. Bird Gard is an electronic devise that mimics the distress call of various birds including the eastern blue jay and the attack call of a hawk. This alone is only moderately effective for a short time. Coupled with several Scare Eye balloons hanging 4 metres up around the orchard, the results were remarkable. Control lasted all season long at the Grimo hazelnut orchard.