You do not need to prune a cobnut tree to make it produce nuts. However, if you never prune it, the tree will probably grow to more than 7m (20ft) tall. You will not be able to reach the nuts while they are in their 'green' succulent stage and will need to wait until they are ripe and ready to fall from the tree. The traditional method of pruning cobnut trees involves checking the height of the tree to within the reach of a picker, about 2m (7ft). The branches are thinned out and trained outwards to make a bowl-shaped tree on a short trunk.
Pruning normally takes place in winter and early spring, say from mid-November to mid-April. Firstly remove dead, diseased and broken wood. The tree must then be pruned so that it is sufficiently open to encourage the production of flowers and allow access for picking. Each tree should have 6-8 framework branches growing outwards. If there are too many, those which are too close should be thinned out to allow space for the others. If there are too few, gaps should be filled, perhaps using suckers. Any unwanted suckers should be removed at the base. Strong shoots will need to be removed from the tree to reduce height and density of growth, and some inwardly-growing shoots may need to be cut out to ensure the centre of the tree is not too dense.
In the near future the Association will provide a download version of our Pruning Booklet for £3.00. This also includes information on establishing new cobnut trees and restoring trees which have become overgrown.