Oak wilt

Symptoms - Oak wilt is not known in the UK, but is widespread in North America where is has killed large numbers of trees.

Red oaks are highly susceptible to infection by the oak wilt fungus. After symptoms first appear, a red oak will generally wilt completely in two to six weeks. The trees wilt from the top of the crown down and individual leaves wilt from leaf tip and margins to the bases, turning bronze to brown. Fallen leaves are often green at the base. White oaks range in susceptibility. Infected white oaks die slowly, a branch at a time, often surviving for many years. Leaf discoloration of affected white oaks resembles autumn colors.