Common Name: large filbert
Type: Deciduous shrub
Family: Betulaceae
Zone: 4 to 8
Height: 12.00 to 15.00 feet
Spread: 12.00 to 15.00 feet
Bloom Time: March
Bloom Description: Yellow
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Suggested Use: Hedge, Naturalize
Flower: Insignificant
Leaf: Colorful, Good Fall
Fruit: Showy, Edible
Culture
Grow in acidic, organically rich, medium moisture, well-drained loams in full sun to part shade. Best in full sun. Tolerates average soils, but not unamended heavy clays. Suckering may occur.
Noteworthy Characteristics
Corylus maxima, commonly called large filbert, giant filbert or giant hazel is typically seen as a large, suckering, deciduous shrub growing 12-15’ tall. It is native from southeastern Europe to western Asia. It is a parent of the hybrid plants (C. avellana x C. maxima) that are commonly grown in commerce for filbert nuts. It is very similar to C. avellana, except it is somewhat more tree-like in habit, its foliage and twigs are sticky-hairy and it has elongated involucre husks that extend well beyond each nut. Double-toothed, broad ovate, dark green leaves (to 5” long) are pubescent. Leaves turn variable but usually unexceptional shades of yellow in fall. Monoecious flowers appear in catkins in spring but are not showy. Edible nuts follow the female flowers. Each nut is encased by an involucre husk that extends beyond the nut. Nuts may be roasted and eaten, or left for the squirrels. The species shrub may be difficult to find in commerce.
Genus name comes from the Greek word korylos, or from korys meaning a helmet, in regard to the husk on the nut.
Specific epithet means largest.
‘Atropurpurea’ is a purple-leaved cultivar that is much easier to find in commerce.
Problems
No serious insect or disease problems. Some susceptibility to leaf spots, blight and crown gall. Occasional insect pests include scale, leafhoppers and various foliage-eating caterpillars. Removal of root suckers, particularly in large plantings, can become time-consuming.
Uses
Shrub borders or naturalized areas. May be grown for nut production.