Corylus sieboldiana - Asian Hazel

The Corylus sieboldiana, also known as the Japanese Hazel, is a Korean and Japanese botanical species related to the common Hazel (Corylus avellana) found in our countryside. It is a beautiful deciduous bush, very hardy and not demanding in terms of soil. It also produces small edible hazelnuts, but they are strangely wrapped in a kind of bristly "elephant trunk", which is quite unpleasant to touch. This Hazel grows attractive male aments in winter and red female flowers in March. For collectors of rare plants!

Corylus sieboldiana belongs to the birch family, like all hazels. It is native to Japan and Korea and is found in mountain forests and thickets. This bush, which can reach 5-6m (16-20ft) in height and over 3m (10ft) in width in our climates, arrived in Western Europe in 1904. It has maintained a discreet place in cultivation. It is a self-fertile and monoecious fruiting bush: the male flower heads, distinct from the female flower heads, are borne in different areas on the same plant. It loses its leaves in winter.

Siebold's Hazel is a reasonably fast-growing bush which can produce suckers from its base. With a bushy habit, it develops multiple small trunks and dense, rounded vegetation. Its bark is grey-brown, initially smooth, becoming rough with age. The young branches are downy, covered with long glandular hairs and have numerous visible round and linear lenticels. The young spring leaves have a decorative dark spot in their centre. The mature leaves are ovate, entire, coarsely and doubly toothed at the edges. The lamina is 6 to 12cm (2 to 5in) long and 4 to 9cm (2 to 4in) wide. It is slightly downy, strongly veined, medium green in colour, and turns golden yellow in autumn before falling.

The male flowers appear on the plant during the summer and bloom in February-March before the leaves appear. They are drooping catkins, bronze-yellow in colour, grouped in 2 to 4, quite decorative. The female flowers, visible in March, are shaped like a bud measuring 6 to 8mm (1in), partially concealing magenta-red stigmas. After pollination, small clusters of hazelnuts form. They are small, surrounded by a thick shell that ends in a long fringed tube. The whole group does not exceed 3cm (1in). Each hazelnut, ovoid in shape, measures just over 1cm (1in) in length. Its hard shell protects an edible seed rich in oil. Their curious shell is sometimes purplish when immature, with dense yellowish and pale brown bristles. They are harvested between September and October. The presence of the slightly irritating shell makes peeling these hazelnuts quite tedious.

This excellent Japanese Hazel prefers to be planted in a free hedge or thicket. It will be satisfied with any soil, preferably limestone, but not too clayey. It is a very hardy tree, not water-demanding, and hassle-free. For example, combine it with amelanchiers, Japanese goumi, male cornel, and other aronias to create a haven for birds and a wild orchard that will delight the curious. Its vegetation provides shelter for wildlife, and squirrels and other wild animals appreciate its hazelnuts.