Updated: Jun 29, 2021
The hawthorn is a deciduous shrub or small tree with spiny, thorny branches and lobed dark green leaves. Mature trees can reach a height of 15m and they can also grow as a small tree with a single stem.
What really sets hawthorn hedges apart are the sprays of scented creamy white or occasionally pink flowers. Once pollinated by insects, they develop into deep-red fruits known as 'haws'. Haws was also the Old English word for “hedges”. Other common names for the hawthorn include quickthorn or maythorn.
The bark is brown-grey, knotted and fissured and twigs are slender and brown and covered in thorns. The wood can be used in turnery and engraving and to make veneers and cabinets, as well as boxes, tool handles and boat parts. It also makes good firewood and charcoal.
Hawthorn is a pagan symbol of fertility and has ancient associations with May Day. The flowers and leaves were often used in Mayday garlands but in medieval times, blossoms were thought to resemble the plague with their pungent aroma, thus were never taken inside a home. In fact, botanists later learned that the chemical trimethylamine in hawthorn blossom is also one of the first chemicals formed in decaying animal tissue, so it is not surprising that hawthorn flowers were associated with death.
The young leaves, flower buds and berries are all edible, and the plants are increasingly valuable herbal medicines. The haws are rich in antioxidants and are eaten by migrating birds, such as redwings, fieldfares and thrushes, as well as small mammals. While hawthorn berries aren’t directly classified as poisonous to humans, there are some instances when they may cause some adverse effects when consumed. The seeds of the fruits in the Rosaceae family are known for containing an amygdalin compound which is basically cyanide that has bonded with sugar. The apple (also from the same family- Rosaceae) has similar seeds to the hawthorn.
The common hawthorn has red aposematic thorns. This means they show a warning colour to fend off predators. The thorns harbour an array of pathogenic bacteria that are much more dangerous to herbivores than the painful mechanical wounding by the thorns.
Common hawthorn can support more than 300 insects. It is the foodplant for caterpillars of moths, including the hawthorn, orchard ermine, pear leaf blister, rhomboid tortrix, light emerald, lackey, vapourer, fruitlet-mining tortrix, small eggar and lappet moths. Its flowers are eaten by dormice and provide nectar and pollen for bees and other pollinating insects.
Small mammals, birds, insects and other invertebrates nest, roost and/or hibernate in the hawthorn, for example: wood mouse, wren, robin, blackbird, song thrush, brimstone and peacock butterflies, lacewing, ladybird, slow worm and the common toad.
Hawthorn makes an excellent hedge and thrives in most soils. Mix it with some blackthorn and holly and you won’t have any human intruders moving in-only animal ones!