What Are the Signs of Ash Tree Disease?

With early detection key to a tree’s survival, a common question our experts come across is, “what are the signs of ash tree disease?”

Many property owners are familiar with the emerald ash borer. However, your ash tree can suffer from several other diseases. Knowing each disease’s symptoms can help determine the appropriate steps.

Read on to learn the signs of common ash tree diseases and how Arvada’s tree service professionals can help.

What Are the Signs of Ash Tree Disease?

Here are some of the most common ash tree diseases and their symptoms.

Emerald Ash Borer

To spot the presence of emerald ash borer, look for cracks in your tree’s highest branches and canopy dieback.

As the adult beetles make their tunnels, they wrap and kill your tree’s branches and trunk. As a result, the tree could develop new shoots on the trunk.

Verticillium Wilt

Common signs of the verticillium wilt include yellowing leaf edges and sudden wilting on several branches. Additionally, the wood under the outer bark of drooping branches could develop discolored streaks.

Ash Anthracnose Disease

This ash tree disease causes leaves to develop large tan or black patches. You may also notice tiny purple-to-brown spots at the center of the leaves.

In extreme cases, the ash anthracnose disease can cause distortion and complete defoliation.

Ash Yellows

Ash yellows impact ash trees of all ages, with symptoms appearing three years after infection.

Infected trees tend to have thinner, smaller, and lighter green leaves and grow slower than healthy trees. The trees could also grow branches in clumps.

Ash Flower Gall

The ash flower gall is a disease brought on by eriophyid mites.

What are the signs of ash tree disease here? A tell-tale sign of this disease is the presence of greenish, round, one-inch tumor-like structures known as galls.

These galls turn woody and dark brown in late summer and could cause severe leaf distortion.

Banded Ash Borer

The banded ash borer is another harmful beetle that, unlike the emerald ash borer, attacks diseased, stressed, dying, or dead trees.

Adult beetles deposit eggs in the tree’s bark, which hatch into larvae that feed under the bark. These tunneling larvae weaken the tree’s limbs, making them vulnerable to storms and strong winds.

Though you can easily confuse the banded ash borer’s infestation with the emerald bash borer, there is a way to differentiate the two. Banded ash borers’ tunnels curve and zigzag without direction and have round exit holes. Alternatively, an emerald ash borer will leave behind a D-shaped exit hole.

Disease Management in Arvada, CO

Though these diseases have killed millions of ash trees, turning to the treatments our team at Arbor Pro Tree Experts Co. provides can save your tree. Speak with our knowledgeable staff by calling (303) 935-0005, and let us help you prevent the destruction of your ash tree population.

We are always ready to answer all tree-related questions, such as, “what are the signs of ash tree disease?” and “what trees turn red in fall?” Call us today with your questions!

Our goal at Arbor-Pro Tree Experts is to be the best quality tree care company at a reasonable price. Call us today for a free estimate. You will be treated with fast, friendly, and expert tree service.

Contact Us

6405 W Mississippi Ave
Lakewood, Colorado 80226


(303) 935-0005

(303) 935-2568

Monday- Friday: 7:30 AM- 4:00 PM