Emerald ash borer in Ohio, and what it means for the ash stump in your yard

Emerald ash borer, or EAB, is the reason so many ash stumps stand in Cincinnati, Dayton and Northern Kentucky yards. This guide covers what the beetle is, when it arrived, what a dead ash stump does, and who handles ash trees on the tree lawn. Every outside fact comes from a university, a state agency, the federal government or a city page, and each is named.

What is emerald ash borer?

Emerald ash borer is an invasive beetle from Asia that kills ash trees. USDA APHIS says it is responsible for the death and decline of tens of millions of ash trees in North America. The adult is metallic green and about one-half inch long.

Ohio State University Extension (OSU) describes the damage this way in its BYGL newsletter. The larvae bore into the layers under the bark and feed. Their winding tunnels, called galleries, destroy the tree’s vasculature (the tubes that carry water and nutrients). Over time they girdle the tree, which means they cut off the flow up and down the trunk.

The beetle came from outside North America. OSU says it arrived in the Detroit, Michigan area in the late 1990s and was first detected in 2002. APHIS also dates the first North American detection to 2002 in southeast Michigan. APHIS says it has detected infestations in 38 States and the District of Columbia.

For more on the beetle itself, see the glossary entry for emerald ash borer and the entry for ash tree.

When did emerald ash borer reach Cincinnati and Dayton?

OSU Extension says the beetle was confirmed in Hamilton County in 2007. Hamilton County holds Cincinnati. In the same article, an OSU author says untreated ash trees in southwest Ohio “went to ashes” quickly in the years that followed, and that eventually few trees were left to feed the beetle.

Here is a short timeline from the sources.

Cincinnati Parks Urban Forestry measured the city’s tree canopy in 2000 and again in 2010. It found a 2 percent decrease and names the arrival of the emerald ash borer as the driving force. That is the city’s own statement about the loss.

In Dayton, the city’s Urban Forest Master Plan page says Ohio was among the first states affected by the beetle. The page also says Dayton’s urban forest has been heavily affected by invasive pests, disease and severe weather. A separate post covers what the Dayton plan means for your tree lawn.

Forest Park, in Hamilton County, ties its dead tree program to the same pest. The city says that from aging trees to various infestations (Emerald Ash Borer), large segments of its trees have died or are dying. A post on the southwest Ohio timeline lays out these dates in more detail.

Is the emerald ash borer still in Ohio?

Yes. Ohio State University Extension published “Emerald Ash Borer Still Infesting Trees” on July 1, 2026. It says that even though the initial infestation wave has long passed, the beetle is still present in forests and landscapes, infesting new ash seedlings and resprouting ash.

The same article adds two cautions for tree owners. Lingering ash trees are still at risk. Trees that were protected by insecticides could be at risk if treatment is discontinued.

An earlier OSU article from June 2023 explains why. It says the beetle populations crashed after most large ash died, but they never went to zero. Then, in OSU’s words, EAB “has experienced a reversal of fortune.” Multi-stemmed ash in the southwest part of the state began to lose stems. OSU’s stated lesson is that EAB will be with us for years to come.

Kentucky has a parallel record. The Kentucky Division of Forestry says infestations were first confirmed in the state in 2009. Its 2022 Forest Health Highlights report says EAB has been confirmed in 103 Kentucky counties and expects the beetle to affect ash across the entire state. The guide on emerald ash borer status in Ohio and Kentucky covers the current picture.

How do I know if my ash is infested?

Look for a set of signs together, not one. USDA APHIS lists dead branches high in the crown, excessive branching on tree trunks and vertical cracks in the bark. It also lists D-shaped exit holes, which are small holes left where adult beetles emerged, and more woodpecker activity.

OSU Extension adds details. Canopy dieback starts high in the crown and works down. Suckers (shoots) then sprout from the trunk base. Bark can pop off the trunk and show winding tunnels under it. Woodpeckers may flake off bark and leave a lighter, “blonde” look on the trunk.

These signs can come from other problems. This guide does not diagnose a tree. If you think you have EAB, APHIS has a report form and a phone line, 1-866-322-4512. An ISA Certified Arborist can inspect the tree.

The glossary has an entry for the D-shaped exit hole.

What happens to a dead ash stump?

A dead ash stump can still send up growth. The beetle does not kill the base of the tree. OSU Extension says “EAB only kills the above-ground portion of their ash hosts.” That means new growth could and did resprout from the base.

The sources do not describe how fast an ash stump decays. The guide on dead ash tree stumps covers what to look for and your options.

For how long any stump takes to rot, the stump grinding versus stump removal pillar compares the main choices. The after-grinding guide covers what is left behind.

Why do dead ash stumps send up shoots?

The cause is simple. The beetle kills the tree above ground, but the roots and the base can stay alive. OSU Extension says ash regeneration “became evident in southwest Ohio as early as 2008” from the base of dead trees and stumps. It calls the multi-stemmed result “bush ash.”

OSU compares this to American chestnut and chestnut blight. The fungus does not kill the chestnut’s root system, so chestnut sprouts still appear in the woods until the fungus finds them again.

For ash, the cycle repeats. OSU says the new stems were attacked as soon as they reached enough girth to support EAB larvae. That kept a steady supply of beetles in the area, even as total numbers fell.

Three terms matter here:

• Bush ash: multi-stemmed ash growing back from a dead tree or stump.
• Stump sprout: a shoot that grows from a stump.
• Sucker: a shoot that grows from the base of a trunk or from a root.

The sources for this guide do not say whether grinding a stump stops the shoots. They also do not say how far roots must be removed. For those questions, read will a stump grow back and do roots die after stump grinding. A stump killer product is a separate subject, covered in does stump killer work. If you use any chemical product, follow the product label.

Can I treat an ash tree instead of removing it?

Sometimes. OSU Extension says treatment can protect an ash tree if it is not too far gone. Once a tree is about 30 percent defoliated, the effectiveness of treatment goes down, and the tree may be too far gone to rescue. OSU names systemic insecticides as the products used, and says they must be used early and repeated every year to every two or three years.

OSU also notes that larger trees need a professional who injects the tree. APHIS says treatment options are available at local retail outlets and that your local Cooperative Extension agent is a resource. OSU says: “Follow all label instructions when using insecticides for any purpose as the label is the law.”

OSU’s 2023 article raises another point: treat or replace is a choice to revisit. It says tree owners should run the math on removal, particularly if significant defects or health issues have emerged.

This site does not give pest-control advice beyond those sources. A tree that is already dead is a removal and stump question, not a treatment question.

What does Kentucky say about EAB?

The Kentucky Division of Forestry says infestations were first confirmed in Kentucky in 2009. In its 2022 Forest Health Highlights report, it says EAB has been confirmed in 103 Kentucky counties. It also says the county quarantine system ended in April 2014, when the entire state was added to the USDA APHIS list of regulated areas.

APHIS removed its domestic EAB quarantine regulations in 2020. APHIS still says people contribute to long-distance spread when they move EAB-infested ash firewood, logs or nursery stock, and it asks buyers to use only local firewood or certified heat-treated firewood.

For Northern Kentucky, the Covington page covers street trees: see Covington street tree permits and your stump. The local hub is stump grinding in Northern Kentucky.

Who removes ash trees on the tree lawn?

The tree lawn is the strip between the sidewalk and the street. The rules differ by city, so this section names what each office says.

Cincinnati. Cincinnati Parks Urban Forestry oversees tree maintenance within public rights-of-way. The city requires a Public Tree Work Permit before work on or near a public tree. The page also says that when a permit-holder removes a public tree, they must pay the appraised value of the tree plus the cost of removal and stump grinding before approval. For the stump request route, see who grinds the stump in front of my Cincinnati house.

Forest Park. The city’s dead or dying tree program excludes street trees, meaning trees between the sidewalk and the street. It also says cosmetic work such as stump removal is contracted separately and paid directly by the resident.

Dayton. The Urban Forest Master Plan page says the city is studying its trees through June 2027. It does not set a rule for the tree lawn. Contact the city before you act.

See also the tree lawn and right-of-way glossary entries, and the guide on who owns the stump on the tree lawn.

Before you grind

Ground-disturbing work has its own steps. Read before you grind: 811, tree lawn and permits first. It covers what OHIO811 and Kentucky 811 say, and it covers private lines, which the owner must mark.

A stump that is ground leaves wood chips. The chip haul-away and topsoil service page explains the haul-away option. Ask about it when you request your free estimate.

Next step

If you have a dead ash stump in Dayton, Cincinnati or Northern Kentucky, the stump grinding service page shows how the work runs. Call (513) 587-6772 or send photos for a free estimate.