Corylus Americana American Hazelnut is a deciduous, rounded, multi-stemmed shrub that grows 8-16 feet tall. Male flowers emerge in beautiful, 2-3 inches long, yellowish brown catkins in the spring, but female flowers emerge in tiny, reddish, unnoticeable catkins. Small, delicious nuts in the shape of eggs produced by female flowers and enclosed in leafy, husk-like, ragged-edged bracts mature in July and August. The ovate, double-toothed, dark green leaves come in various colors throughout the fall, from eye-catching blends of orange, rose, yellow, and green to dull yellowish green. American Hazelnut prefers average, medium, well-drained soil in full sun to part shade and is ideal for hedges.