Tree of the Month from Sidmouth Arboretum: The majestic horse chestnut

Sidmouth Herald: Not all of the flowers produce conkersNot all of the flowers produce conkers (Image: Archant)

Continuing Sidmouth Arboretum's series Tree of the Month, we are focussing on tree 1472 from the Arboretum's database, the large Horse Chestnut or Conker Tree (Aesculus hippocastanum) in the Lawns area of The Byes.

This is one of the largest trees in The Byes standing next to the Sweet Chestnut that was featured in July's Resident. At 25m (80ft) tall and with a girth of 5.1m (almost 17ft), tree 1472 is over 200 years old. There are many other splendid Horse Chestnuts around Sidmouth. There are several in the park of the Knowle, in the churchyard and in front of Kennaway House. There is a very large one growing at the junction of Winslade Road and Alexandria Road.

Horse Chestnut or Conker trees are native to the Balkan peninsula and were introduced to Britain in the seventeenth century. The timber is pale and soft and of little value except to wood carvers. They grow quickly into tall, elegant trees and, with their profusion of flower spikes in May that look like so many white candelabra, they soon became popular as statement trees in parks and large gardens.

Horse Chestnuts are easy to identify at any time of year. In winter, the twigs have large sticky buds arranged in opposite pairs and the scars from old leaves are shaped like a horseshoe with nail marks where the veins joined the leaf to the twig. In spring and summer, the large, palmate (like a hand) leaves are quite unlike any other common tree except near relatives such as the Yellow Buckeye (Aesculus flava) that stands in the cemetery and the Indian Horse Chestnut (Aesculus indica) that is by the driveway to the former council offices at Knowle. In the autumn of course there are conkers emerging from their spiky cases when they fall to the ground. At first, the large seeds are white, but they turn brown when they are exposed to the air. In the USA, their cousins are called Buckeye trees because the seeds are said to resemble the eye of a deer.

Sidmouth Herald: Bleeding canker causes leaves to wilt.Bleeding canker causes leaves to wilt. (Image: Archant)

Horse Chestnuts are in the Soap Berry family and the conkers are rich in chemicals called saponins. Ground conkers can be used as a 'Viking soap' although Vikings probably never saw a conker. In the past, they also served as a horse medicine for coughs and stomach complaints, hence the name. Saponins can be poisonous and so it is best not to confuse Horse Chestnuts with Sweet Chestnuts.

Although an introduced species, Horse Chestnuts support a lot of British wildlife. The flower spikes are a mixture of male, female and hermaphrodite flowers and are a rich source of nectar and pollen for bees. The leaves are eaten from the inside by leaf miners which causes an ugly brown scarring in late summer, but the trees seem to cope with this. The leaf miners are a favourite food of blue tits. Deer and other mammals eat the conkers. Each year several Indian Horse Chestnut seedlings pop up in my garden because squirrels collect and bury conkers from the tree in the Knowle which is just behind my garden fence.

Apart from the leaf miners, Horse Chestnuts are threatened by a fungal disease, Bleeding Canker. The fungus grows under the bark and causes a blackish weeping from cracks in the bark. It blocks the water-carrying tube cells in the trunk cutting off the water supply from the roots. The leaves wilt, and the tree dies.

The game of conkers seems to have started as a uniquely British pastime. According to the World Conker Championship website, the first recorded game of conkers is believed to have taken place in the Isle of Wight in 1848. The World Conker Championships started in Ashton, Northamptonshire in 1965. It started as a bit of fun when a group of regulars at the local pub couldn't go fishing because of bad weather. Someone suggested they have a conkers competition. A small prize was awarded to the winner and a collection was made for charity by someone who had a blind relative. They repeated the event the following year and, as word spread, more people joined in. It became an annual event with entrants increasing in number and any resulting money being donated to the Royal National Institute for the Blind for Talking Books. The event has become so popular, it has had to move to another village with more space. It is now truly international and, like football and cricket, we now have people from around the world coming to us and beating us at our own game.

Sidmouth Herald: Not all of the flowers produce conkersNot all of the flowers produce conkers (Image: Archant)

Ed Dolphin is Treasurer of Sidmouth Arboretum, visit the Arboretum website to find out more about the trees of Sidmouth by clicking here.

To read more features from East Devon Resident, click here.