What emerald ash borer is and why it's a big deal
Emerald ash borer (EAB) is a small metallic-green beetle whose larvae tunnel under the bark of ash trees, cutting the tree's vascular system until it starves. It attacks all true ash species (green ash, white ash, and the Arizona/Texas ash widely planted in DFW), and it is nearly always fatal to an untreated ash once an area is infested. EAB has spread relentlessly across North America and is now confirmed in the North Texas region — which moves it from “if” to “when” for local ash trees.
How to spot it
Early EAB is hard to see because the damage starts high in the canopy. Watch for: canopy thinning and dieback starting at the top; D-shaped exit holes (about 1/8 inch) in the bark; serpentine, S-shaped tunnels under loose bark; vertical bark splits; unusual woodpecker activity (“blonding” where birds strip bark to eat larvae); and water-sprout shoots erupting from the trunk and base as the tree responds to stress. By the time canopy dieback is obvious, the tree is often well into infestation.
Treat or remove? The honest framework
The decision comes down to the tree's value, health, and your tolerance for an ongoing commitment. A healthy, well-placed, structurally-sound ash that you value — a real shade tree over a patio or providing significant canopy — is usually worth treating, because treatment is highly effective when started before major canopy loss. An ash that is already declining (more than ~30–50% canopy loss), poorly placed, structurally poor, or simply not important to your landscape is usually better removed and replaced before it dies and becomes a brittle hazard.
What treatment involves and costs
EAB is treated with systemic insecticide — most effectively by trunk injection (emamectin benzoate), which protects the tree for about two to three years per treatment. It is not a one-time fix: a treated ash is a tree you commit to injecting on a cycle for as long as you want to keep it. DFW treatment costs vary with trunk diameter but are generally a few hundred dollars every couple of years — often far less than removing and replacing a large mature ash, and it keeps the canopy you already have. Treatment must start before the tree is too far gone to respond.
If you remove: do it before it's a hazard
Dead ash wood becomes brittle and dangerous remarkably fast — EAB-killed ashes are notorious among arborists for unpredictable, sudden limb and trunk failure, which makes them more dangerous and more expensive to remove the longer you wait. If you decide an ash isn't worth treating, remove it while it's still sound and safe to climb or reach, then replant with a tough, non-ash DFW species (bur oak, cedar elm, chinquapin oak, or Texas red oak) so you're not relying on a single vulnerable species.
What we recommend for DFW ash owners
Have your ash assessed now, before symptoms force a rushed decision. We evaluate the species, size, health, structure, and placement, give you a straight treat-or-remove recommendation with the real numbers for each path, and — if treatment makes sense — start it early enough to actually protect the tree. The worst outcome is doing nothing: an untreated ash in an infested area is on a clock, and waiting only narrows your options and raises the eventual removal cost.