Holes in Ash Tree Leaves: Reasons and Solutions

If you have an ash tree on your property, you may have noticed that its leaves are starting to develop holes. This can be a cause for concern, as it may indicate a problem with the tree. In this blog post, we will discuss the possible reasons why your ash tree’s leaves are developing holes, and we will provide solutions to help address the issue.

Why Are There Holes in Ash Tree Leaves?

The ash sawfly is the most common insect pest that is responsible for holes in ash tree leaves, which is a type of fly that looks like a wasp. The female sawfly will lay her eggs on the underside of the leaves, and when the eggs hatch, the larvae will begin to feed on the leaf tissue. This feeding can cause large, irregular holes to form in the leaves.

While the ash sawfly is the most common culprit, there are other insects that can also cause damage to ash tree leaves. These include weevils, Japanese beetles, and caterpillars. In some cases, the damage may be caused by diseases such as leaf spot or anthracnose.

You may not even know that your ash tree is infested with insects until you start to see the damage on the leaves. If you notice holes in the leaves of your ash tree, it is important to take action immediately to prevent further damage.

How to Treat Ash Tree Leaves with Holes?

It’s important to treat ash tree leaves with holes as soon as possible. If the problem is caused by insects, you will need to take steps to control the population of the pests. This can be done by using insecticidal sprays or treatments, or by removing the affected leaves from the tree.

I’ve had good success with neem oil, which is a natural insecticide that is derived from the neem tree. Neem oil will kill the insects that are causing damage to the ash tree leaves, and it is also effective at controlling fungal diseases.

Simply mix the neem oil with water according to the instructions on the bottle, and then spray it onto the affected leaves. Be sure to cover both the top and bottom surfaces of the leaves, as this will ensure that all of the insects are killed.

Ash holes
Ash holes

If you have a severe infestation, you may need to repeat this treatment every week or two until the problem is under control.

In addition to using neem oil, you can also try to remove the affected leaves from the tree. This will help to reduce the population of insects, and it will also prevent them from causing further damage.

How to Keep Pests Away From Ash Tree?

Once you have the pests under control, you will need to take steps to prevent them from returning. The first step is to keep your tree healthy and resistant to pests.

Be sure to water your ash tree regularly, as this will help it to stay healthy and strong. You should also fertilize your tree every year, using a fertilizer that is specifically designed for ash trees.

You can also use traps or barriers to keep pests away from your ash tree. For example, you can use sticky traps to catch Japanese beetles, or you can install a fence around the tree to keep deer away.

Finally, keep your garden clean and free of debris, as this will help to deter pests from taking up residence near your ash tree. Plus, you’ll have an easier time spotting pests if they do try to infest your tree.

By following these tips, you can help to prevent holes from forming in ash tree leaves. If you do find that your tree is infested with pests, be sure to take action immediately in order to prevent further damage.

What Else Causes Holes in Ash Tree Leaves?

There are a few other reasons why holes might form in ash tree leaves. For example, if the leaves are exposed to too much sun, they can develop small holes or cracks.


Bigger animals can also cause damage to ash tree leaves. Birds, squirrels, and other animals may nibble on the leaves, which can create small holes. In some cases, animals may also strip the bark from the tree, which can cause larger holes to form.

Protecting your ash tree from animals is similar to protecting it from pests. You can use repellants or barriers to keep animals away from your tree. You can also try to scare them off by making loud noises or using motion-activated sprinklers.


Extreme weather conditions can also cause damage to ash tree leaves. For example, if the leaves are exposed to high winds, they can become battered and torn. In addition, if the temperature drops suddenly, the leaves may develop frost damage.

There is not much that you can do to protect your tree from weather damage. However, you can try to minimize the damage by covering your tree with a tarp or burlap during extreme conditions.


Finally, disease can also cause holes to form in ash tree leaves. Ash trees are susceptible to a number of different diseases, including leaf spot and powdery mildew. These diseases can cause the leaves to develop brown spots or patches, which can eventually lead to holes.

Treating diseases is similar to treating pests. You will need to use a fungicide to kill the pathogens that are causing the disease. Be sure to follow the instructions on the label carefully, as using too much can damage your tree.

Should I Prune Ash Tree Leaves with Holes?

It’s a good idea to prune your ash tree if a fungal disease is present to help prevent the spread of the disease. If you find that your tree is heavily infested with pests, you may also want to prune the affected leaves to help reduce the population.

Pruning ash tree leaves is a simple process. Just use sharp, clean pruning shears to cut off any affected leaves. Be sure to dispose of the leaves properly, as they can continue to harbour pests or diseases.


To conclude, the holes in ash tree leaves can be caused by pests, disease, weather damage, or even animals, but the ash sawfly is usually the culprit. Be sure to take action immediately if you find that your tree is infested with pests or diseases.

Do you have any tips for preventing or treating holes in ash tree leaves? Let us know in the comments below!

Leave a Comment