Common Tree Diseases in Ohio

Every tree service company in the Tri-State region has a short list of certain tree diseases to check for each time we inspect a yard. These diseases vary from season to season. Sometimes one particular infection spreads like wildfire — it could be due to that season’s humidity, or insect habitation patterns, or wind currents.

Tree Diseases In Ohio You May Find

Here are the five that we look for the most when we take care of your landscaping.

1. Cedar Apple Rust

This is mainly on crabapple and apple trees, though it can happen with red cedar trees too. The leaves develop yellow spots, which eventually turn orange. Cedar Apple Rust is a fungus.

2. Apple Scab

This is a nasty fungus too, and it also hits crabapple and apple trees. Apple Scab leaves different colored spots on the tops and bottoms of leaves and fruit. The tops of leaves will have green or yellow spots, while the bottoms will carry dark spots. The fruit itself will have reddish-brown looking rot on it, which somewhat resembles the type of scab you might get if you skin your knee or elbow.

3. Thousand Cankers

Walnut trees are susceptible to this disease, which is carried by Walnut Twig Beetles. The beetles burrow into the bark and leave behind a fungus, which attacks the tree’s circulatory system.

4. Powdery Mildew

Powdery Mildew disease is so dangerous, in part, because so many different trees and plants can catch it. Unlike many other arbor diseases, that focus on one or two types of trees, this is more like the common cold. Tiny white-or-grey fungal spores can overtake the leaves, making it look like the leaf is covered in sugar or salt.

5. Needlecast Diseases

These hit our coniferous trees — Douglas Firs, Spruces, Pines, etc. The new needles on these trees can carry a fungus, and it turns sections of each new green needle to a black or dark brown shade.