Hazel (Corylus avellana)
Hazel is a deciduous broadleaf tree native to the UK.
Common name: hazel
Scientific name: Corylus avellana
UK provenance: native
Interesting fact: hazel is so bendy in spring that it can be tied in a knot without breaking. Bees find it difficult to collect hazel pollen and can only gather it in small loads. This is because the wind pollinated hazel has pollen that is not sticky and actually repels one grain against another.
A year in the life of a hazel tree
What does hazel look like?
Overview: hazel is often coppiced, but when left to grow, trees can reach a height of 12m, where it can live for up to 80 years (if coppiced, hazel can live for several hundred years). It has a smooth, grey-brown, bark, which peels with age, and bendy, hairy stems. Leaf buds are oval, blunt and hairy.
Leaves: round to oval, doubly toothed, hairy and pointed at the tip. Leaves turn yellow before falling in autumn.
Flowers: hazel is monoecious, meaning that both male and female flowers are found on the same tree, although hazel flowers must be pollinated by pollen from other hazel trees. The yellow male catkins appear before the leaves and hang in clusters, from mid-February. Female flowers are tiny and bud-like with red styles.
Fruits: once pollinated by wind, the female flowers develop into oval fruits, which hang in groups of one to four. They mature into a nut with a woody shell surrounded by a cup of leafy bracts (modified leaves).
Look out for: leaves are soft to the touch as a result of the downy hairs on the underside. Hazel is often coppiced.
Could be confused with: elm (Ulmus minor var. vulgaris) leaves are similar however elm leaves are roughly hairy unlike soft hazel leaves. Elm leaves have an asymmetric leaf base.
Identified in winter by: each nut is held in a short leafy husk which encloses about three quarters of the nut. Small green catkins can be present in autumn.
Where to find hazel
It grows across much of Europe, parts of north Africa and western Asia. In the UK it's often found in the understorey of lowland oak, ash or birch woodland, and is also found in scrub and hedgerows.
Value to wildlife
Hazel leaves provide food for the caterpillars of many moths, including the large emerald, small white wave, barred umber and nut-tree tussock. In managed woodland where hazel is coppiced, the open wildflower-rich habitat supports many species of butterfly, particularly fritillaries. Coppiced hazel also provides shelter for ground-nesting birds such as the nightingale, nightjar, yellowhammer and willow warbler.
Hazel has long been associated with the dormouse (also known as the hazel dormouse). Not only are hazel nuts used by dormice to fatten up for hibernation, but in spring the leaves are a good source of caterpillars, which dormice also eat.
Hazel nuts are also eaten by woodpeckers, nuthatches, tits, wood pigeons, jays and a number of small mammals. Hazel flowers provide early pollen as a food for bees.
The trunks are often covered in mosses, liverworts and lichens, and the fiery milkcap fungi grows in the soil beneath.
Mythology and symbolism
Hazel has a reputation as a magical tree. A hazel rod is supposed to protect against evil spirits, as well as being used as a wand and for water-divining. In some parts of England hazel nuts were carried as charms and/or held to ward off rheumatism. In Ireland hazel was known as the 'Tree of Knowledge’, and in medieval times it was a symbol of fertility.
How we use hazel
Hazel wood can be twisted or knotted, and as such it historically had many uses. These included thatching spars, net stakes, water divining sticks, hurdles and furniture. Hazel was also valued for its nuts, or 'cobs'.
Today, hazel coppice has become an important management strategy in the conservation of woodland habitats for wildlife. The resulting timber is used in many ways, and is becoming increasingly popular as pea sticks and bean poles, used by gardeners.
Hazel was grown in the UK for large-scale nut production until the early 1900s. Cultivated varieties (known as cob-nuts) are still grown in Kent, but most of our hazelnuts are now imported.
Hazel is not known to suffer from any particular pest or disease, but it may occasionally be attacked by aphids, gall mites and sawflies. Coppiced hazel is susceptible to deer damage if not protected.