Each month, Arbor Masters® will highlight the best trees and plants for the Midwest, providing pros and cons as well as maintenance tips for each species.

Black gum

What is Attacking My Trees?

Our cool wet spring has brought out a host of diseases that are attacking trees, shrubs and landscapes. While there are many diseases affecting landscapes, below are the most prominent diseases seen recently by our Certified Arborists.

Dothistroma (needle cast fungus) and Diplodia (tip blight fungus) attack pine trees. The fungus appears in late April and May, especially during a wet spring, causing the pine needles to brown and drop prematurely. The fungus can spread to other pines and without a fungicide treatment, will severely damage or kill the tree. 

Dutch elm is a vascular wilt fungus and is transmitted from one tree to another by the European and native elm bark beetles. The fungus can also be transmitted via root grafts. Trees planted within 25 to 50 feet of each other can easily develop grafted root systems and quickly spread the disease.

Oaks, birch, walnut, ash, sycamore or maple trees can suffer from Anthracnose. This fungus can attack trees causing premature leaf loss and branch dieback. This disease affects a wide variety of tree species and treatments will vary depending on the species of tree.

While there are numerous diseases that can affect your trees and landscape, most can be brought under control or eliminated. The diseases listed above should be treated with a fungicide application. Certain trees will benefit from a spray application, others species may require a systemic trunk injection to allow the fungicide to uptake throughout the tree. Your Arbor Masters® Certified Arborist can advise which treatment is best for your trees.