Sunday, 21 October 2012

Bonkers about Conkers!


Every little boy – and many a gown-up one as well – loves to play conkers at this time of year.  Or at least, I assume they still do; it is possible that it may have been banned from the school playground under health and safety grounds.  When you think of it – not only did we frequently impale our hands with the meat skewer we had pinched from the kitchen drawer to pierce the conkers with, we quite often cut ourselves with our penknives as we trimmed the strings to the right length. And what about those shattered splinters flying through the air like vegetative shrapnel – no-one thought about wearing eye protection then.



However, the traditional sport of conkers isn’t threatened so much by legislation as by the recently imported leaf miner moth (Cameraria ohridella) which first appeared in southwest London in 2002.  With no predators it has spread at an alarming rate and now it is reckoned that nearly all trees in England and Wales are infected by it.  The moth’s presence can be detected by the brown-black blotches that cover the leaves, disrupting the trees ability to synthasise fully.  This in turn weakens it which has made them much more susceptible to disease, especially bleeding canker which is now threatening their very existence.   In some years, leaf damage is more severe and the leaves can drop very early indeed.  As a consequence, some trees are looking in very poor shape.
 
 
 

The secret valley has numerous mature Horse Chestnuts.  They are fine trees, up to 100ft or more tall and look especially splendid in spring, their white flower spikes contrasting with the freshness of their newly opened green leaves which, at that time of year, are still unblemished.  In the 400+ years since they were introduced to Britain from the Balkans, they have become an integral part of a child’s growing up.  We learnt how branches of the ‘sticky’ buds, the dormant leaf buds, becoming ever more shiny and sticky as the sap rises within the tree, can be cut and forced to open into leaf early in a jam jar of water.  On hot summer days we learnt, usually when lying beneath the trees in their cooling shade, how to make ‘fish bones’ by shredding the leaves with our fingers until just the skeletal veins of the leaves remained.  When we wanted to be nasty we knew that we could hurl the hard, green nutshells armed with their sharp spikes to embed in our enemy’s backs or scratch their legs if they were wearing shorts.  And, of course, we held conker competitions.


Horse Chestnuts in full bloom on a fine late spring day
 
Now with all the trials of pests and disease plus the dreadful summer weather, conkers are few and those that have matured barely half their normal size.  It has even been suggested that brussel sprout competitions may have to be held instead although I doubt if they will give the satisying dull thud of the real thing even if they were frozen first.  However, this years World Conker Championships have taken place this month as normal – it was first held in 1965 and, unlikely as it seems, attracts competitors from all around the world.  You can find out more by clicking on the link below.
Not all is gloom and doom for the Horse Chestnut for it is now thought that some bird species are beginning to learn about this new food source and research is being carried out by the University of Hull and others to monitor this suspected behaviour.  There is little that we, as gardeners or conservationists can do at this stage to assist other than to report any signs we see of birds feeding on the trees.  We just have to hope that the Horse Chestnut doesn’t disappear from our countryside in the same way that the Elm did in the 1970’s and 80’s.


The difference in size between the two trees is quite marked - as is the autumnal tints of the frost damage part of the smaller one 
 
In the secret valley, we also have a number of the smaller, red flowered Horse Chestnut, Aesculus x carneaca, and this does not seem to become infected to the same degree as the white flowered, Aesculus hippocastanum.  Although they do produce conkers unfortunately they are neither of a size or quality suitable for a serious round of conkers.  Horse Chestnuts, by the way, are poisonous to horses – they get their common name by the scars on the branches where the leaves once were: a perfect horseshoe complete with marks where the nails would be. 
 


When you get to know a place intimately – whether it’s a garden or a landscape – you notice things that the casual observer misses.  In the late spring of 2011, we had a biting frost that killed off not all but some of the new young growth of numerous trees – just where it touched.  Some trees remained unscathed, others  were totally destroyed and some just part.  This is what happened to one of a pair of Horse Chestnuts visible from our little stone cottage.  One tree has always been much more stunted than the other, although as their girths are the same, I assume they were planted at the same time.  They stand side by side but one, when the river bursts its banks is under water for a few days longer than the other.  Is it this that has caused it to be so much shorter or is it this rare burning of the leaves by frost?  It took months for the tree to recover, finally sending out new spring green leaves and flower buds at the end of July contrasting greatly with the remainder of the tree whose leaves had not been harmed.  Likewise, the older leaves turned their autumn colours and fell earlier than the newer ones.  This year the tree, which now looks quite poorly, has reversed with the damaged leaves turning golden – in the ten days since the photograph was taken, they have fallen while the remaining leaves are yet to get their autumn tints.



Almost hidden from view, our old stone cottage stands well above the little winding river


 In 2011, we had a very late frost blackening both the leaves and flowers - it took months for the tree to recover

 
The secret valley will be a much poorer place if all the Horse Chestnuts succumb to disease and have to be felled.  Let us hope that future generations can play beneath them as we have done.



Sources:
British conkers getting smaller
World Conker Championships
Conker Tree Science Project





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