A Technical Report from The Bartlett Tree Research Laboratories
Box blights are caused by two fungal diseases known as Volutella buxi and Cylindrocladium buxicola. In combination these two fungal diseases form the most conspicuous problem to affect box (Buxus sempervirens) and its cultivars within the UK and Ireland. Both fungi can occur individually or in combination on the same plant. Volutella has been present within the UK and Ireland for many years. Volutella buxi results in browning of the leaves and dieback of branches leaving bare patches in hedges and topiary specimens. The fungi spread in wet humid conditions. Pinkish spores appear on the undersides of leaves and are carried in water splashes to new sites. Fallen leaves carry the fungi over the winter and new spores are produced in the spring. Volutella buxi enters the plant through clipping cuts and other forms of damage to the leaves and stems.