What Are the Signs of Ash Tree Disease?

Ash Trees are beautiful and add charm to landscapes. However, like all living things, they are susceptible to diseases, including Ash Tree Disease. This disease can spread rapidly and cause irreversible damage if not addressed promptly. As an ash tree owner, it is crucial to identify signs of the disease and take immediate action.

This blog aims to educate readers on the signs of Ash Tree Disease, common pests and the necessary steps to combat it.

Identifying the signs of Ash Tree Disease


The Branches

One of the initial signs of Ash Tree Disease is branch death or thinning. Look for dead branches without buds or leaves. If you observe these signs, it’s best to have a certified arborist inspect the tree as they are often early indicators.

Bark Discoloration

As the disease advances, the bark cracks and peels, appearing gray and yellow. Prompt action is crucial to protect the tree, as the damaged bark can be harmful.

Crown Dieback

Ash Tree Disease can lead to crown dieback, especially in advanced stages. Thinning crowns, falling leaves, and dead branches are clear indications of the disease affecting your Ash Tree.


An increase in woodpecker activity on your Ash Tree may be an early warning sign of Ash Tree Disease. These birds feed on the tree’s larvae and can target weakened trees. Watch out for this indication, as the disease can compromise the tree’s strength.

Leaf Symptoms

Changes in leaf color, size, and shape can also signal Ash Tree Disease. Leaves may appear smaller, wilted, or yellowish-green and may have dark spots.

5 Common Ash Tree Diseases and Pests

Here are the most common ash tree diseases and pests that pose a threat to their health and longevity.

Emerald Ash Borer (EAB)

EAB is an invasive species mostly found in the United States and Canada and is the most severe pest threat to ash trees.


Anthracnose is a fungal disease that can affect several hardwood trees, including ash trees.

Ash Yellows

Also known as Ash witches’-broom, this disease mostly affects white ash trees and causes abnormal leaf and branch growth.

Verticillium Wilt

It starts infecting the tree’s roots and spreads its way up through the water-conducting tissues, causing yellowing, wilting, and defoliation of leaves.

Scale insects

The most common scale insect that affects ash trees is the oystershell scale. Symptoms include yellowing of leaves, cracking of bark, and a sticky sap on the tree’s surface.

Preserving the Elegance: Safeguarding Ash Trees for Future Generations

Ash trees, like any other living organism, are susceptible to various diseases and pests that can damage their health. By identifying tree disease and insect management early on, we can preserve and maintain the health of these elegant trees for many generations to come. Maintaining healthy ash trees for the environment’s benefit is an essential work that all of us can contribute to.

HiLow Pest Control is a leader in insect pest control and ash tree protection. We specialize in developing long-term strategies to prevent the destruction of ash trees due to common scale insect invaders like oyster-shell scale. To get started, reach out to us today and learn how we can help protect your ash trees for future generations.