Nature Notes - Horse Chestnut by Ian Brand

I have been out collecting conkers. It is a story that all started back in spring, when we were all confined to our homes. I often found myself standing at the kitchen sink looking out of the window at a beautiful Horse Chestnut tree in the field opposite. It filled me with both hope and joy. Its sticky, resinous buds burst into leaf, followed by a magnificent display of cream coloured blooms, looking like a candelabra straight out of “Downton Abbey”! It was then that I decided to challenge my nephew to a game of conkers. So, I am now out collecting them and trying to remember how to produce a “champion” conker. Do you let them dry out slowly on the windowsill, roast in the oven along with the Sunday dinner or soak in vinegar?

Horse Chestnut (Aesculus hippocastanum) was introduced from the Balkans in 1615 and grown for its aesthetic qualities rather than timber. Capability Brown (1716-1783) was very fond of the tree and planted it widely. Slowly the Horse Chestnut escaped those country estates and was first recorded in the wild in 1815. In Germany, Horse Chestnuts are often found in beer gardens. Prior to the advent of mechanical refrigeration, brewers would dig cellars for the secondary fermentation or lagering of beer. To further protect cellars from summer heat, they planted chestnut trees, with their spreading, dense, canopies but shallow roots, which would not intrude on the cellars. The practice of serving beer at these sites has evolved into the modern Biergarten; “Prost”!

The British Government had very different reasons for encouraging children to collect conkers in the First World War. The conkers were required as an alternative form of starch used to produce acetone. This was an essential component of cordite, which had replaced gunpowder as a propellant for military shells by the end of the 19th century.

Finally, the origin of that name “Horse Chestnut”. The Horse epithet has several possibilities. Most likely refers to the horseshoe-shaped scars left on twigs after the leaves have fallen, including five to seven small bumps looking like nailholes where the veins entered the leaf stalk. “Chestnut” is much easier, chosen in the erroneous belief that it was related to the Sweet Chestnut. Although their ‘nuts’ do look similar they belong to completely different plant families. The Horse Chestnut is also mildly toxic and not edible.

Now back to the search for that champion conker!