Common Hazel

? Common Hazel Conservation status: Secure
Common Hazel leaves and nuts
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Fagales Family: Betulaceae Genus: Corylus Species: C. avellana
Binomial name
Corylus avellana L.

The Common Hazel (Corylus avellana) is a shrub native to Europe and Asia. It typically reaches 3-8 m tall, but can reach 15 m on occasion. The leaves are deciduous, rounded, 6-12 cm long and across, softly hairy on both surfaces, and with a double-serrate margin.

The flowers are produced very early in spring before the leaves, and are monoecious, with single-sex catkins, the male pale yellow and 5-12 cm long, the female very small and largely concealed in the buds, with only the bright red 1-3 mm long styles visible. The fruit is a nut, produced in clusters of one to five together, each nut held in a short leafy involucre ('husk') which encloses about three quarters of the nut. The nut is roughly spherical to oval, 15-25 mm long and 12-20 mm broad, yellow-brown with a pale scar at the base. The nut falls out of the involucre when ripe, about 7-8 months after pollination. It is readily distinguished from the closely related Filbert (Corylus maxima) by the short involucre; in the Filbert the nut is fully enclosed by a beak-like involucre longer than the nut.

The name of the species, avellana is derived from Avellino, a place in Italy.

Cultivation and uses

The Common Hazel is an important component of the hedgerows that were the traditional field boundaries in lowland England. The wood was traditionally grown as coppice, the poles cut being used for wattle-and-daub building and agricultural fencing.

Common Hazel is cultivated for its nuts in commercial orchards in Europe, China, Australia and Turkey. The name "hazelnut" applies to the nuts of any of the species of the genus Corylus. This hazelnut or cobnut, the kernel of the seed, is edible and used raw or roasted, or ground into a paste. The seed has a thin, dark brown skin which has a bitter flavour and is sometimes removed before cooking.

In the USA, Hazelnut production is concentrated in two states, Oregon and Washington; however, they are also grown extensively just to the north, in the Fraser Valley of British Columbia. In 1996 the production in Oregon was about 40,000 tonnes (in shell) compared to 200 tonnes in Washington. Recent orchard plantings in California are likely to increase the home production in the USA. The hazelnut is also growing in popularity in the USA with the Hazelnut Council set up to promote its use. The harvesting of hazelnuts is either by hand in rural communities, or by manual or mechanical raking of fallen nuts.

Hazelnuts are extensively used in confectionery to make praline and also used in combination with chocolate for chocolate truffles and products such as Nutella.

In Austria and especially in Vienna Hazelnut paste is an important ingredient in the world famous 'Torts (such as Viennese Hazelnut Tort) which are made there.

Hazelnut is also becoming popular as an addition to the range of coffees drunk by the modern Café society with Hazel Latte becoming popular. The popularity of Hazelnut liqueur, based on a vodka, is now increasing especially in eastern Europe.

In the USA home production of hazelnut butter is seen as an alternative, tasty and more nutritious than its peanut butter counterpart.

In Australia over 2000 tonnes are imported annually mostly to supply the demand from the Cadbury company for inclusion in its eponymous milk chocolate bar which is the third most popular brand in Australia. Hazelnut oil, pressed from hazelnuts, is strongly flavoured and used as a cooking oil.

Hazelnuts are also grown extensively in Australia in orchards growing varieties mostly imported from Europe.

One of the reasons for the nutritional and culinary success of the Hazelnut lies in its nutritional composition. The flesh of a typical nut includes 16% protein and 62% unsaturated oil. In addition it contains significant levels of Thiamine and Niacin and high levels of Calcium, Phosphorus and Potassium.

There are many cultivars of the Hazel including 'Barcelona', 'Butler', 'Casina', 'Daviana', 'England', 'Ennis', 'Halls Giant', 'Tonda Gentile', 'Delle Langhe', 'Tokolyi', 'Cosford', 'Tonda di Giffoni', 'Tonda Romana', 'Wanliss Pride', 'Willamette', 'Lewis', 'Clark' and 'Jemtegaard'. Some of these are grown for specific qualities of the nut including early and late fruiting cultivars, whereas other are gown as pollinators. The majority of commercial Hazelnuts are grown as grafts onto stock of the Turkish Hazel (Corylus colurna), because of its non-suckering habit.