Anthracnose of Shade Trees

Anthracnose is one of the most common and important foliage diseases of shade trees in Iowa. Symptoms of anthracnose are often referred to as “leaf blights” or “leaf spots” and are most serious on sycamore, ash, maple, white and bur oak, and walnut. Linden, hickory, elm, red and black oak, and other deciduous trees also are susceptible, although anthracnose is less common and damaging on these species. Tree owners often become concerned about the possibility of permanent damage to tree health when anthracnose develops. In most cases, although symptoms may appear serious, damage caused by anthracnose is minimal and does not seriously harm established shade trees.