ESTABLISHMENT AND PROVENANCE OF WALNUT IN BRITAIN

This article reviews the silviculture of walnut in Britain and considers the case for planting common walnut (Juglans regia) or black walnut (Juglans nigra), neither of which is native to Britain. In addition the results of four provenance experiments planted in southern Britain in 1986-87 are described. The results of the experiments., confirm that walnut is extremely sensitive to site conditions and should only be planted on the most suitable frost free, fertile, well drained and deeply rootable sites. Species comparisons show that J. nigra is more tolerant of poor sites than J. regia, but at the only suitable site for planting walnut there was little difference between the two species. Vermont, Ohio and Illinois provenances of J. nigra all performed well on the best site in the Chilterns and relatively well on the other poorer sites.