British Native Trees
and Shrubs

Hornbeam Carpinus betulus (Betulaceae)

One of the most striking features of the hornbeam is its deeply fluted trunk and smooth, grey bark which often shines like steel. A slow-growing deciduous tree, it reaches up to 30 m in height but may take 100 years to do so. The ascending branches form a rounded crown and the alternate,oval leaves are similar to those of beech but slightly narrower and longer, 8-10 cm, with double-toothed margins and 9 -15 pairs of more prominent veins. They are dark green above and paler below and less shiny than beech leaves. They turn yellow and gold in autumn. The minute, green flowers are arranged in pendulous, unisexual catkins and appear in April before the leaves have unfurled. The yellowish males with orange anthers are 1.5-5 cm, a little longer than the leafy-looking green female catkins with narrow, curved-back bracts and red styles. The latter elongate up to 14 cm after fertilization and are composed of clusters of small, ribbed nutlets, each attached to a trilobed ‘wing’ for wind dispersal.

Hornbeam is found in oak or mixed woods, often showing signs of having been coppiced or pollarded. It is a lowland species, native only south of a line from the Wash to the Bristol Channel, and grows well on heavy clays which is why pollarded hornbeams were a feature of woods on London clay in Middlesex, Hertfordshire and Essex.

It makes an excellent hedging plant which when cut keeps its leaves throughout the winter. As a specimen tree it is attractive and trouble-free, hardier than beech and with leaves that will withstand late spring frosts and provide autumn tints. In a smaller garden It can be controlled by coppicing or pollarding and it grows on clay or lighter soils but not those that are sandy and acid. It is easily raised from seed gathered and sown in the autumn, which will germinate the following spring. After two or three years seedlings should be planted in place from October to March.

Creamy-yellow hornbeam wood is so strong and hard that it was used in making watermill wheels and the hubs of cartwheels and is still used for piano hammers and chopping blocks. It was also once a major source of fuel.

The leaves are host to several different miners and the larvae of small moths, including the copper underwing caterpillars and nut-tree tussock caterpillars. The seeds are a staple food of hawfinches in autumn and winter. Like birch, hornbeam is often covered in ‘witches-brooms’ caused by a small fungus, Tephrina carpini.

Page last updated - January 10, 2002  

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