Emerald Ash Borer Is Spreading in Texas: What Houston Ash Owners Should Know

On June 4, Texas A&M Forest Service announced that emerald ash borer had turned up in three more Texas counties: Young, Montague and Clay, all up in North Texas, all confirmed from adult beetles caught in the agency’s monitoring traps. That makes ten years since the beetle was first found in the state, in Harrison County in 2016, and the list of confirmed counties has kept growing since.

As of that announcement, no county in the Houston area was on the list. That’s the honest answer to the question we’ve started getting, and it’s worth reading the rest anyway, because this is an insect that has never stopped at a county line yet.

What it does to an ash

Emerald ash borer is a small metallic-green beetle from Asia. The adult isn’t the problem. The larvae are. They feed in the layer just under the bark, the part of the tree that moves water and sugar, and they carve winding S-shaped tunnels through it until the tree can no longer feed itself.

Texas A&M Forest Service says all 16 native ash species are at risk, and that in areas where the beetle is well established it can kill an ash within a year of the first infestation. Trees that look fine in June can be in real trouble by the following summer.

The part that makes it hard to catch: early infestations may show few or no outward signs. By the time an ash is obviously sick, the beetle has usually been in it for a while.

How to check an ash tree

You need to know you have an ash first. Ash leaves are compound, five to nine leaflets on a stalk, set opposite each other on the twig rather than staggered. The bark on a mature tree has a tight diamond pattern of ridges. Green ash is native to this part of Texas and turns up in older yards and along creeks and bayous.

Once you know it is an ash, walk around it and look for these, which are the signs the Forest Service lists:

• Dead branches near the top of the tree. Decline starts in the upper canopy and works down.
• Leafy shoots sprouting from the trunk. A tree losing its top tries to grow a new one lower down.
• Woodpecker activity that seems excessive. Woodpeckers find the larvae before people do. Patches of bark flecked off by birds are one of the earliest visible signs.
• Bark splitting. Vertical splits that expose the S-shaped galleries underneath.
• D-shaped exit holes. About an eighth of an inch wide, flat on one side, left by adults emerging from the bark. Most borers leave round holes. The D shape is the fingerprint.

If you find galleries under split bark or D-shaped holes, the Forest Service asks that you call the EAB hotline at 1-866-322-4512. Reporting a symptomatic tree is how the confirmed-county map gets updated, and it’s how your neighbors find out the beetle is here before their own trees show it.

What the options are

The Forest Service frames it as a decision about the tree’s value, and that’s a fair way to think about it.

A tree worth keeping can be treated. Systemic insecticides with emamectin benzoate as the active ingredient are the recommended option, applied by trunk injection, and the Forest Service says one treatment can protect a tree for two to three years. That is a recurring cost for the life of the tree, so it makes sense for a large ash shading the house or one with real history behind it, and less sense for a volunteer along the back fence.

A tree that is not worth that gets removed, and the wood stays put. Chip it or burn it on site. Don’t stack it for later and don’t haul it anywhere. The larvae are inside the wood, and moving firewood is how this beetle has crossed most of the distance it has covered.

The Texas Department of Agriculture puts quarantines on confirmed counties that restrict moving firewood, ash nursery stock and ash timber out of the area. The Forest Service’s broader advice applies everywhere: buy firewood where you burn it, and do not transport it, even within the state.

An ash that is dead or mostly dead should not be left standing near anything it could hit. A dead ash over a roof is a storm problem waiting for a storm. We wrote about reading a dead or dying tree in the Humble area, and the same signals apply here.

What to do this month if you have an ash

Nothing dramatic. Check it. Look at the top of the canopy from the street, look at the trunk up close, and check again in late summer when this year’s adult beetles would have emerged.

Water it properly through the summer. A stressed tree of any species draws pests, and an ash that is already struggling through a dry stretch is a worse candidate for treatment if the beetle does arrive.

If the tree matters to you, decide now, while it’s healthy, whether it is one you would pay to protect. Treatment works on a tree that is still mostly intact. It doesn’t bring back one that has already lost half its canopy.

Where we come in

We’re not the ones who confirm a county. That’s the Forest Service’s job, and the hotline is the right first call for a tree with the signs above. What we do is read the tree with you, tell you plainly whether it is an ash and whether what you are seeing looks like borer damage or something more ordinary, and handle the removal if that is where it lands. A dying ash near a structure is a removal we plan carefully, not a rush job.

Ask for a free estimate and we will come take a look. We cover Houston, Kingwood, Humble, Conroe, The Woodlands, Spring, Tomball, Cypress and Katy.

Sources: Texas A&M Forest Service’s June 4, 2026 announcement of emerald ash borer detections in Young, Montague and Clay counties, and the agency’s emerald ash borer identification and management guidance.