Get to Know the Most Common Tree Diseases

March 20, 2017

Do your trees not look as vibrant or healthy compared to when they were first planted? Unfortunately, your trees could be dealing with a type of disease. Most tree diseases result from a particular bacteria or fungi.

Check out the selection of common tree diseases below.

Dutch Elm Disease

This fungal disease infects the vascular system of the American Elm, resulting in the clogging of vascular tissues that prevent water movement. The tree wilts and eventually dies. Dying branches are an initial indicator of Dutch Elm Disease, so the best way to diagnose is to cut a live branch and see if there’s any brown streaking in the sapwood.

Tree Blight

Are your trees experiencing wilting, browning of leaves or dieback of leaves and twigs? Tree blight, caused by bacteria and fungus, could be the culprit.

Leaf Scorch

This one can be especially prevalent in the extreme weather conditions of Chicago. Leaf scorch can be visible in the browning or dead areas of a leaf.

Verticillium Wilt

This soil-born fungus results when a tree’s leaves suddenly yellow, wilt and die over an extended period of time. Homeowners will note that the wood and vascular system under the bark of the infected area is discolored in streaks.


Anthracnose commonly affects Dogwood, Ash, Oak and Sycamore trees. The fungal disease causes leaf blight and leads to brownish blotches and discoloration.


This particular tree fungus causes orange or reddish brown swollen areas on a leaf known as galls and cankers. Rust is typically seen on apple trees.


Speaking of galls, they are labeled as abnormal growth of tree tissue caused by parasites from fungi and bacteria, insects or mites. Galls look like large growths on a tree’s trunk, branch, twig or leaf.


Chlorosis stems from the yellowing of leaves due to lack of Chlorophyll. It’s generally caused by a lack of nutrients in the soil, high pH, drought, or even soil compaction. Ironically with chlorosis, the leaf veins will stay green while the rest of the leaf yellows.

Sooty Mold

If you find a black growth on the surface of your tree’s leaves, it could be sooty mold. This fungus grows on honeydew deposited by aphids.

Black Knot

This disease is most common among cherry and plum trees. Black Knot can be identified as a warty swelling on the bark caused by a fungal disease.

Keep in mind that this is just a sampling of tree diseases and that there are much more. At Pro Tree Service, we specialize in high-quality tree removal service. Our staff strives to make your yard look great, which oftentimes means removing dead or unhealthy trees.

Since 1989, Pro Tree has been providing unrivaled services to Chicago and surrounding suburbs. We can provide a free estimate for having your tree(s) removed and then professionally remove them at the most affordable rates.

There’s no need to call a local arborist. Instead, call the experts at Pro Tree Service and have those ugly trees removed today.

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