What to Know About Emerald Ash Borer in Minnesota
The Emerald Ash Borer (EAB) is one of the most destructive tree pests ever to hit the United States—and it’s causing widespread damage here in Minnesota. If you have ash trees on your property, knowing how to identify, manage, and prevent EAB infestations is critical.
At Iron and Oak, we’ve helped countless homeowners protect their landscapes from this invasive insect. Here’s what every Minnesota property owner needs to know about the Emerald Ash Borer.
What Is the Emerald Ash Borer?
The Emerald Ash Borer (Agrilus planipennis) is a metallic green beetle native to Asia. It was first discovered in the U.S. in 2002 and found in Minnesota in 2009. Since then, it has spread rapidly across the state, killing millions of ash trees.
EAB larvae tunnel beneath the bark, cutting off the tree’s ability to transport water and nutrients. Within just a few years, even large, healthy-looking ash trees can be completely dead.
👉 Learn more from the Minnesota Department of Agriculture EAB Resource Page.
Why Is Emerald Ash Borer a Problem in Minnesota?
Minnesota is home to nearly one billion ash trees—more than any other state. These trees are common in yards, parks, and forests, making EAB a huge environmental and economic threat.
Key issues caused by EAB include:
-
Tree Death – Once infested, untreated ash trees typically die within 3–5 years.
-
Property Damage – Dead trees become hazardous and must be removed before they fall.
-
Costly Removal – Large-scale removals across neighborhoods and cities are expensive.
-
Loss of Shade & Value – Ash trees provide shade, windbreaks, and property value—all lost when trees die.
Signs of Emerald Ash Borer Infestation
Unfortunately, EAB damage isn’t always obvious until it’s advanced. Watch for these warning signs on your ash trees:
-
D-shaped Exit Holes – Adult beetles leave tiny, D-shaped holes in the bark.
-
S-shaped Galleries Under Bark – Larvae carve winding tunnels that disrupt the tree’s nutrient flow.
-
Thinning Canopy – Branch dieback starts at the top and works downward.
-
Epicormic Sprouts – New shoots growing from the trunk or roots indicate stress.
-
Woodpecker Damage – Increased woodpecker activity often signals larvae under the bark.
Treatment Options for Ash Trees
If caught early, some ash trees can be protected. Treatments include:
-
Systemic Insecticides – Applied through trunk injections or soil drenches, these chemicals protect trees by killing EAB larvae.
-
Preventative Treatment – Best for healthy trees not yet heavily infested.
-
Tree Removal – Severely infested or declining trees may need to be removed before they pose safety risks.
👉 Learn more about our tree removal services and tree care options at Iron and Oak.
Should You Treat or Remove Your Ash Tree?
The decision depends on:
-
Tree Health – Healthy trees with less than 30% canopy loss may be worth treating.
-
Location – Trees near homes, driveways, or sidewalks pose safety hazards if left untreated.
-
Cost – Treatment can be more affordable than removal, but repeated applications are needed every 2–3 years.
-
Long-Term Goals – If you want to preserve the shade and beauty of your ash trees, treatment may be the best option.
Our certified arborists can evaluate your trees and recommend the most effective plan for your property.
How to Protect Your Property
-
Have your trees inspected – Early detection is key.
-
Don’t move firewood – EAB spreads when infested wood is transported.
-
Consider treatment – Start preventive care before symptoms appear.
-
Plan for replacement – Diversify your landscape with other species to avoid future pest issues.
Final Thoughts
The Emerald Ash Borer is here to stay in Minnesota, but with the right plan, you can protect your property and avoid costly damage. Don’t wait until your ash trees are beyond saving—early action is the most effective way to fight back.
At Iron and Oak, we offer professional EAB inspections, treatment options, and safe removal services. Our goal is to help Minnesota homeowners preserve their landscapes while staying safe.