Emerald Ash Borer Treatment in Lansing: What's Worth It in 2026

Published May 2, 2026 by Lansing Tree Services

Emerald Ash Borer rolled through Ingham County hard. The first confirmed Michigan finds in 2002 were in Wayne County, and by the late 2000s the bug had killed millions of ash across the state. We've climbed thousands of dying ash in Lansing, East Lansing, Okemos, Holt, Haslett, DeWitt, and Mason. Most are dead or gone. The ones that are still alive in 2026 are either survivors that got lucky or trees that have been on a treatment program.

This guide is for the homeowners holding onto a still-healthy ash and trying to decide whether to keep treating it, start treating it for the first time, or call us to take it down. We'll walk through how the treatment actually works, what it costs, when it makes sense, and the warning signs that say the window has closed.

How EAB Treatment Works

The treatment that actually works in 2026 is trunk injection of emamectin benzoate, sold under brand names like TREE-age and TREE-age G4. A certified arborist drills small holes around the base of the trunk, plugs in pressurized injection ports, and forces the chemical into the vascular system. The tree's own xylem carries the active ingredient up through the trunk and out into every branch and leaf. EAB larvae feeding on the inner bark hit a lethal dose, and adult beetles laying eggs on a treated tree die before their offspring can establish.

Emamectin benzoate is the gold standard because the chemistry stays active in the tree for two full growing seasons, sometimes three on smaller, healthier trees. The competing options (soil drenches with imidacloprid, basal sprays, and bark sprays) are weaker, shorter-lived, and need annual re-application. Cost-effective treatment in Lansing means trunk injection on a 24- to 36-month rotation. Anything else is throwing money at the problem.

Michigan State University's Department of Entomology and the U.S. Forest Service have both published extensively on emamectin efficacy, and the results are consistent across studies: properly applied trunk injection prevents new EAB damage on healthy ash with above 90 percent reliability for the duration of the chemical's active life.

What Treatment Actually Costs in Lansing

Pricing in mid-Michigan in 2026 lands roughly in this range:

Now compare that to removing and replacing. Taking down a 24-inch ash in a residential lot in the Lansing area runs $1,200 to $2,400 for the removal alone. Add stump grinding ($150 to $400), site cleanup, and a replacement tree large enough to fill the canopy gap (a 3-inch caliper hardwood costs $400 to $700 plus planting), and you're at $1,800 to $3,500 for a tree that won't reach mature canopy for 25 years.

For a 24-inch DBH ash that's still healthy, you can fund 6 to 8 treatments before the math flips. That's 12 to 16 years of preserved canopy, mature shade, and full property value. Treatment is almost always the better economic call when the tree is treatable.

The 60% Canopy Rule

The most important number in this whole conversation is the percentage of the canopy that's still alive. Treatment effectiveness drops fast as the canopy fails because the tree's vascular system, the highway that distributes the chemical, gets disrupted by EAB feeding damage in the cambium.

• 80 to 100 percent canopy alive: Excellent treatment candidate. Expect normal results.
• 60 to 80 percent canopy alive: Strong candidate. Treatment will hold the line, may not fully recover existing dieback.
• 40 to 60 percent canopy alive: Marginal. Some success possible, but the tree may continue to decline. Get a second opinion before committing.
• Under 40 percent canopy alive: Removal is usually the right call. Treatment rarely saves a tree this far gone.

Look at the top of the tree, not the lower limbs. EAB damage shows up at the top first because the larvae attack mid-canopy and starve the upper limbs first. A tree that looks fine at eye level but has 30 percent of its top dead is already past the easy-treatment window.

Spotting EAB Damage Before It's Obvious

By the time bark splits and woodpecker damage are visible, the tree has been infested for 2 to 4 years. Catching it earlier means better treatment outcomes. The signs we look for in spring assessments:

Top-Down Canopy Thinning

Compare the upper third of your ash to the lower two-thirds. If the top is sparse and the bottom is full, that's classic early EAB damage. Stand 50 feet from the tree and look up. A healthy ash should have a uniform canopy density top to bottom.

Epicormic Sprouting

Tufts of small leaves sprouting directly from the trunk or large branches are the tree's stress response to crown loss. Some species do this naturally, but on a mature ash it's a warning sign. The tree is trying to grow new leaves wherever it can because the original canopy is failing.

Woodpecker Damage

Pileated and hairy woodpeckers love EAB larvae. If the bark on your ash is being stripped in patches and you can see lighter wood underneath, the woodpeckers have found a meal. We've called dozens of EAB infestations off woodpecker activity alone before any other sign was visible.

Bark Splitting and S-Shaped Galleries

By the time bark is splitting in vertical strips, the larvae have been feeding for at least one full season. Pull back a piece of loose bark and look for the serpentine, S-shaped galleries packed with sawdust-like frass. That's the larvae's feeding pattern. Once you see galleries, you're past the early treatment window for that tree.

D-Shaped Exit Holes

About 1/8 inch wide, flat on one side and rounded on the other. Adult beetles emerge through these from late May through July in mid-Michigan. A tree with multiple exit holes has been hosting EAB through at least one full life cycle.

The Right Time of Year to Treat

Timing matters. Trunk injection works best when the tree is actively transpiring, because transpiration is what pulls the chemical up through the vascular system. In the Lansing area, that means:

• Mid-April through early June: Prime treatment window. Full leaf-out, warm soils, strong sap flow.
• June through July: Still effective, especially for larger trees that need more chemical and longer uptake time.
• August: Workable, but uptake starts slowing as days shorten.
• September on: Generally too late. The tree is pulling back resources for dormancy.
• Winter: Wait until next spring. Injection into a dormant tree won't circulate.

If you're starting fresh on a tree we've never treated before, the first injection should happen in spring, with a follow-up assessment a year later to confirm the tree responded. We don't push annual treatments because the chemical lasts 2+ years; over-treating wastes money and creates more wound sites on the trunk.

When Removal Makes More Sense Than Treatment

Some ash trees should come down. The decision tree we use on every site visit:

1. More than 50 percent canopy dieback in the upper crown. Treatment will not recover this. Schedule removal before structural failure.
2. Vertical bark splits on more than 30 percent of the trunk. The cambium is too damaged to circulate chemical. Tree is functionally dead.
3. The tree leans over a structure or driveway. Compromised ash trees fail at the upper trunk and shed limbs unpredictably. The risk equation favors removal.
4. The tree is in a high-target area. Roof line, kid play area, parked vehicles. We get conservative on hazard calls when the consequence of failure is high.
5. Cost of treatment over 10 years exceeds removal plus replacement plus 5 years of replacement establishment. Rare on healthy trees, common on marginal ones.

If we're called for an estimate and the tree is past the treatment window, we'll tell you. Our tree removal service handles ash takedowns with crane access for the trees that have grown into trouble. Storm-damaged ash get prioritized through emergency response when needed.

What Replacement Looks Like After Removal

Mid-Michigan's tree canopy needs species diversity going forward. The lesson of the EAB invasion is that monocultures collapse. We recommend planting one of these instead of another ash:

• Bur oak (Quercus macrocarpa): Native, slow but extremely durable, beautiful long-term shade tree.
• Swamp white oak (Quercus bicolor): Faster than bur oak, tolerates wet feet common in Lansing soils.
• Northern hackberry (Celtis occidentalis): Tough, fast, good urban tolerance, similar form to ash.
• Kentucky coffeetree (Gymnocladus dioicus): Native, late to leaf out, no pest pressure.
• Yellowwood (Cladrastis kentukea): Smaller scale, beautiful flower display.

Stay away from anything in the Fraxinus genus (white ash, green ash, blue ash, all hosts) and don't plant maples in a yard that already has them. Diversify.

Frequently Asked Questions

How much does emerald ash borer treatment cost in Lansing?

Emamectin benzoate trunk injection in the Lansing area runs roughly $9 to $15 per inch of DBH per treatment in 2026. A typical 18-inch DBH ash tree costs around $200 to $280 per treatment. Injections are repeated every 2 to 3 years for healthy trees. Cost scales with diameter, access, and how many trees are being treated at once.

When is the best time to treat an ash tree for EAB?

The best time is mid-spring through early summer (mid-April through June) when the tree is actively transpiring and adult EAB beetles are emerging. Late-season injections work but uptake slows as the tree pulls back for fall. The tree must have full leaf-out and warm soil for the injection to circulate properly through the canopy.

Should I treat my ash tree or just remove it?

Treat if the canopy is at least 60 percent intact, the trunk is sound, and you value the tree (shade, privacy, property value). Remove if more than 40 percent of the canopy is dead, the bark is splitting in vertical strips, or the tree is over a structure. Treatment of a tree past 50 percent canopy loss usually fails because the vascular system is too compromised to circulate the chemical.

How long does ash borer treatment last?

Trunk-injected emamectin benzoate (sold as TREE-age and similar) protects an ash tree for 2 to 3 years per treatment. Soil drenches with imidacloprid last 1 year and are weaker. Most arborists recommend the longer-lasting trunk injection for valuable trees because the protection per dollar is significantly better, and fewer applications mean fewer wounds.

What does an ash tree with EAB look like?

Look for thinning canopy at the top, dead branches in the upper third of the tree, vertical bark splitting that exposes serpentine S-shaped galleries in the wood beneath, D-shaped exit holes about 1/8 inch wide, and aggressive woodpecker activity on the trunk and main limbs. By the time bark splits are obvious, the tree has been infested 2 to 4 years.

Is treatment worth it after EAB has been in Lansing this long?

Yes, if the tree is still healthy. EAB pressure in the Lansing area has dropped from peak years because most untreated ash are gone, but residual beetles still cycle through surviving trees. A protected ash continues to gain value as a survivor. Treatment also costs far less than removal plus replacement, especially for trees over 18 inches DBH.

The ash trees still standing in 2026 in mid-Michigan are the survivors. Some are surviving because they got lucky and never got hit hard. Most are surviving because someone made the call to treat them. If you have an ash on your property and you're not sure where it stands, get an arborist on it before the next flight season starts in late May. Earlier is always better than later on this one.

Related reading: Tree Disease Diagnostics | Tree Removal in Lansing | Emergency Tree Service | Pruning and Trimming