There’s a fungus among us! Verticillium wilt is a fungus that can be found in a variety of ornamental trees and shrubs, commonly used in Illinois landscapes. Examples of susceptible trees include, but are not limited to, the Horse Chestnut, Kentucky Coffee tree, Redbud and Maples. Susceptible shrubs include Barberry, Viburnum, Serviceberry and Spirea.
Symptoms of this fungus include curled or wilted leaves, yellowing or reddened foliage, falling leaves and dead branches. Proper diagnosing is important, since these symptoms are very similar to many other plant diseases. As the fungus progresses, more branches are affected and may die. Verticillium wilt starts in the root system and travels upwards through the plant. An infected tree or shrub can take several years to succumb to the fungus. Ordinarily, plants in Illinois are more susceptible during cool or warm weather, as opposed to very hot weather conditions.
Prevention is the key with this fungus. Proper watering and fertilization are excellent control methods. For example, use a fertilizer lower in Nitrogen and higher in Potassium on susceptible plant species. If you suspect Verticillium wilt is present in your landscape, please contact the Plant Health Care Department at KTS to have it properly diagnosed and treated.