Emerald Ash Borer in St. Louis: Should You Treat or Remove Your Ash Tree?

What Is the Emerald Ash Borer and Why Should St. Louis Homeowners Care?

The emerald ash borer (EAB) is an invasive beetle native to Asia that has devastated ash tree populations across North America since its discovery in Michigan in 2002. This metallic green insect is small, measuring just half an inch long, but the damage it causes is catastrophic. The larvae tunnel beneath the bark of ash trees, disrupting the tree's ability to transport water and nutrients, ultimately leading to tree death within two to four years of infestation.

St. Louis has been dealing with emerald ash borer populations for over a decade. The pest arrived in the region around 2008 and has since spread throughout the city and surrounding areas. If you own ash trees on your property, understanding the threat posed by this beetle is essential to protecting your landscape and making informed decisions about treatment versus removal.

Signs Your Ash Tree Is Infested with Emerald Ash Borer

Early detection is crucial when dealing with emerald ash borer in St. Louis. One of the most telling signs of infestation is the appearance of small, D-shaped exit holes in the bark, typically about the size of a pinhead. These holes are where adult beetles emerge after completing their larval stage beneath the bark. You may also notice vertical splits or cracks in the bark as the tree attempts to compartmentalize the damage caused by tunneling larvae.

Other warning signs include crown dieback, where the upper branches of the tree begin to thin and die, along with increased woodpecker activity as birds feed on the beetle larvae beneath the bark. Ash trees may also produce epicormic shoots, which are small branches sprouting directly from the trunk as a stress response. If you notice any combination of these symptoms on your ash trees, it's time to consult with a professional arborist who can assess the extent of the infestation and recommend the best course of action.

Emerald Ash Borer Treatment Options: Can Your Tree Be Saved?

If caught early, some ash trees can be treated to prevent emerald ash borer damage. The most effective treatment method is tree injection, which delivers insecticide directly into the tree's vascular system. This approach ensures the pesticide reaches the areas where beetle larvae are feeding, making it far more effective than surface sprays. Professional arborists typically use products containing imidacloprid or emamectin benzoate, which are specifically formulated to target EAB.

Treatment is most successful on trees that are not yet heavily infested and are in good overall health. Trees with less than 30 percent crown dieback have a reasonable chance of recovery with proper treatment. However, treatment is not a one-time solution. Most ash trees require annual injections to maintain protection, which means committing to ongoing care and expense. Additionally, treatment works best as a preventative measure on trees that show no signs of infestation yet. Once a tree is severely compromised, treatment becomes less effective, and Tree Removal becomes the more practical option.

Ash Tree Injection Cost in St. Louis: What to Budget

The cost of emerald ash borer treatment through tree injection varies depending on several factors, including the size of the tree, the health of the tree, and the specific product used. On average, homeowners in St. Louis can expect to pay between $75 and $300 per tree for a single injection treatment. Larger trees or those requiring multiple injection points will fall on the higher end of this range. Since most ash trees need annual treatments to remain protected, you should budget for ongoing annual costs if you choose this route.

When comparing the cost of treatment to removal, it's important to consider the long-term financial commitment. While a single injection may seem affordable, multiple years of treatment can add up quickly. Additionally, if your tree is already showing advanced signs of infestation, treatment may not be cost-effective. For a detailed breakdown of pricing specific to your trees and situation, St. Louis Tree Service offers a free estimate. Call us at (636) 556-6253 to discuss your options with an experienced arborist.

When Removal Is the Better Choice: Assessing Your Options

For many homeowners, Tree Removal is the most practical solution when dealing with emerald ash borer. If your ash tree is already heavily infested, showing significant crown dieback, or has a poor overall structure, removal eliminates the problem entirely and prevents the tree from becoming a hazard on your property. Dead or dying ash trees are prone to branch failure and can pose serious risks during storms or high winds.

Removal also prevents the tree from serving as a reservoir for emerald ash borer populations that could spread to neighboring trees. In some cases, especially if you have multiple ash trees on your property, removing infested trees while treating healthier ones may be the most economical approach. After removal, you'll have the option to plant a new, non-ash species that will thrive in your landscape without the threat of EAB. Following tree removal, you may also want to consider Stump Grinding to completely clear the area and prevent regrowth.

Making the Treatment vs. Removal Decision: A Practical Guide

Deciding whether to treat or remove your ash tree depends on several key factors. First, assess the tree's current health and the extent of infestation. A tree with minimal visible damage and strong overall structure is a good candidate for treatment. Second, consider the tree's location and value to your landscape. If the ash tree is a mature specimen with significant aesthetic or shade value, investing in treatment may be worthwhile. Third, evaluate your budget for ongoing care. If you're willing to commit to annual injections, treatment can extend the life of your tree for many years.

Conversely, if your tree shows advanced signs of infestation, has poor structure, or is located in a high-risk area near your home or power lines, removal is the safer and often more cost-effective choice. Professional arborists at St. Louis Tree Service can evaluate your specific situation and provide expert recommendations tailored to your needs. Whether you're leaning toward treatment or removal, the key is acting quickly. Emerald ash borer populations continue to spread, and early intervention offers the best outcomes. Contact us today at (636) 556-6253 or request a free estimate to discuss the best strategy for your ash trees.