Perhaps the most often asked question about village history in Leigh is ‘How old is the oak tree on the Green outside Oak Cottage?’
Robin Wood, who worked in the past for the National Trust, specialising in the management of pollarded trees, came to the village and has shed some light on various aspects of ‘our’ oak.
In mediaeval times, trees on common land were often pollarded – cut off at about eight or ten feet from the ground – and the resulting wood was used by whichever commoner had the coppicing rights. Quite often the grazing rights and the wood cutting rights were held by different people and the idea of cutting the trees at eight or ten feet was to prevent the livestock from damaging the new growth on the trees. Every twenty years or so the process was repeated.
This practice continued on new trees until about two hundred years ago when the Enclosure Acts were being enacted and common land was being abolished, although the older trees often continued to be cut back until the end of the Victorian era.
This pollarding greatly increased the life span of the tree. In all trees the central heart-wood is dead with all the life being contained in the outside of the trunk. The only growth occurs in the cambium, the few millimetre thick area immediately under the bark. In the old pollarded trees, the dead central heart-wood often rotted away leaving a not very tall hollow cylinder. This shape is much more flexible and better at withstanding winds – which was very apparent in the 1987 hurricane when very few pollarded trees were destroyed but many seemingly strong mature trees were uprooted.
So myths about our oak being hollow because it had been struck by lightening are not correct.
Robin Wood estimates that the oak tree on the Green is about 400 years old although, unless the type of soil and the ‘water supply’ to the tree are assessed, it is difficult to be accurate. There is no easy way of taking measurements or even boring into the trunk to assess the age of a pollarded tree since all the central growth rings have rotted away. A rule of thumb for non-pollarded trees is to measure the “girth at breast height” and very approximately 1” equates to one year though trees grow more slowly on thin dry soil, if subject to root competition or soil compaction. Pollarding also slows the growth since for much of its life the tree will have had a much smaller crown than it does today and so fewer leaves producing fewer nutrients.
Robin Wood, having heard about the work commissioned by the Parish Council a couple of years ago said that it was exactly right – the heavy cut back of the branches and the spiking and aerating the ground beneath the tree to prevent compaction. (The road beside the tree will have done it no favours). He added that another important thing is not to be too tidy and allow the bushy regrowth to occur around the top of the trunk as this will produce the replacement branches of the future. Pollarded trees are fantastic for wildlife often housing rare invertebrates and wherever possibly large dead branches should be kept close to such a tree rather than tidied away.
If the village continues to cherish the oak on the Green, Robin Wood says “there is no reason why it should not live a further 200 years”.
Parish Magazine Article: March 2010:by Chris Rowley