Conker Canker

From the front of the school we look over Hills Road towards the Botanic Garden; and if you stand at the board in room 8, every time you look out of the window your view is dominated by a sickly horse chestnut tree.

ChestnustMarronnierPseudomonasSyringaeThe horse chestnut is in Western Europe is threatened by an incurable pathogen, a new strain of the so-called bleeding canker (Pseudomonas syringae pathovar aesculi), which affects and slowly circles the bark and major branches of the trees, restricting and ultimately cutting off circulation to the crown. Crown dieback is one of the symptoms, and is what we see from room 8 (and in the picture above).

It is also what I see from the windows at the back of my house. We have a horse chestnut in the garden which is dying, and will soon need removing. It is a sad business, also and perhaps especially for my children, for the horse chestnut is the source of the conker.


Conkers is a game played with the fruit of the horse chestnut, known as a conker, which is skewered on a bit of twine and smashed into a rival conker. Last conker standing, so to speak, wins. When I was at school (and I am sure, still today) conkers were valued according to their accumulated victories, like Spitfires; there was solemn debate over whether the victories should be numbered singly, or inherited – whether, in other words, defeating a conker with a given number of victories meant you should claim all of those victories too.

Well, the conkers are on the way out. Nearly half of all horse chestnuts are affected in Britain, and there is no known treatment. In the 1970s we lost almost all of our elm trees to the virulent dutch elm disease, and recently ash trees have similarly been threatened. The landscape is forever changing, and soon, from room 8, we’ll be able to see right into the Botanic Garden, perhaps as far as the systematic beds.

post on our sister blog, OISE Oxford, laments the destruction of avenues of horse chestnuts in Cutteslowe Park, Oxford.