Save your ash trees from EAB with timely injection.
Creative Tree & Stump LLC is a Brighton, CO-based tree removal company serving 22 communities across Adams, Weld, Jefferson, Boulder, Broomfield, and Denver counties. Shawn Brandau, an ISA Certified Arborist who has cared for Front Range trees since 1991, can assess whether your ash is worth protecting, and the company is fully insured. Get a straight answer with a free, no-obligation on-site assessment in Brighton and across the metro.
This matters here because ash is one of the most heavily planted street and yard trees on the Front Range. Whole neighborhoods were lined with green and white ash, which means EAB threatens a large share of the region’s shade canopy — and gives owners of healthy ash a real reason to consider protecting them. Losing a 40-year shade tree and starting over with a sapling is a setback no quick replacement can undo.
Emerald ash borer is sneaky: by the time the symptoms are obvious, the infestation is usually well established. The earliest and most telling sign is thinning and dieback that starts at the top of the canopy and works downward, because the larvae cut off the tree’s plumbing from the crown back. As that happens, the tree often panics and sends up shoots — called epicormic sprouts — directly from the trunk and base, an unmistakable distress signal.
Look closer at the bark for the diagnostic clues: small D-shaped exit holes where adult beetles emerged, vertical bark splits over the larval tunnels, and the winding, S-shaped galleries underneath if a piece of bark is lifted. Heavy woodpecker activity is another giveaway — birds flake off the outer bark chasing the larvae, leaving the trunk looking pale and scuffed. If you are seeing any of these on an ash, it is time for an assessment.
An untreated ash that becomes infested with EAB does not hang on for long. Once the larvae are girdling the trunk, most ash decline rapidly and die within two to four years — there is no recovering a tree that has been fully girdled. Doing nothing is, in effect, choosing removal, just on the insect’s timetable instead of yours.
And waiting makes that removal harder and more expensive. EAB-killed ash dry out and turn brittle quickly, so a dead ash becomes a genuine hazard, dropping limbs and failing in ways that make it dangerous and costly to take down safely. A tree treated proactively, or removed while still sound, is far easier to deal with than one left to die standing — which is the whole reason to make the call early.
The most effective treatment is a trunk injection of emamectin benzoate, a systemic insecticide delivered directly into the tree’s vascular system. The tree moves the product up into the canopy, where it kills the EAB larvae that tunnel beneath the bark — the larvae are what actually girdle and kill the tree, cutting off the flow of water and nutrients. A single injection generally protects a tree for about two years.
Trunk injection is far more reliable on large, established ash than soil-applied or spray products, and because it is injected, it stays in the tree rather than washing into the surrounding soil or lawn. Treatment works best as prevention or early intervention: a tree that is still mostly healthy has the living tissue to move the product and recover, while one that is already half-dead cannot. That is why an honest assessment comes first — there is no point spending money to inject a tree that is already beyond saving.
The rule of thumb is straightforward: treat a healthy, well-placed ash you value, and remove one that is too far gone. If a tree has lost more than 30 to 50% of its canopy, has major dieback in the crown, or is structurally compromised, treatment is a poor investment and removal is the safer, more economical choice. We walk through this with you honestly on our dedicated treat-or-remove decision page.
When removal is the right answer, a dead or dying ash should not be left standing — EAB-killed ash become brittle quickly and are notoriously dangerous to take down once the wood dries out and fails unpredictably. We handle ash and EAB removal as well as treatment, so whichever way the decision goes, the same crew can carry it out. You are not bounced between a treatment company and a removal company arguing over what to do.
Injection is priced by the size of the tree — typically by trunk diameter at chest height — and is repeated about every two years for as long as you want to protect the tree. Because EAB pressure does not go away, treatment is an ongoing commitment rather than a one-time fix: a small price each cycle, but one that continues for the life of the tree.
That is the real comparison behind the decision. Treatment is a modest recurring cost; tree removal is a larger one-time expense, often followed by the cost of replanting and waiting years for a new tree to mature. For a healthy, mature shade tree, ongoing protection frequently pencils out — and you can get a quick ballpark for either path with our cost-estimate tool before booking a free on-site visit. We will lay both numbers side by side so you can decide with the full picture.
EAB was first confirmed in Colorado in Boulder in 2013 — the first detection in the state — and it has since spread across the Front Range. It is now established in communities throughout the Denver metro, and entomologists at CSU Extension and the Colorado State Forest Service expect it to continue moving through the region’s ash population. From Thornton northward, untreated ash are increasingly showing the thinning crowns and dieback that signal infestation.
The insect spreads slowly on its own but quickly when people move infested firewood and wood, which is how it jumps between towns. Across Commerce City and the older tree-lined neighborhoods of Northglenn, the ash that were planted by the thousands decades ago are exactly the trees now at risk, and owners are facing the treat-or-remove decision in real time.
One point CSU Extension stresses is that EAB only attacks true ash trees in the genus Fraxinus — green, white and black ash. Mountain ash is not a true ash and is not a host. And because EAB-killed ash turn brittle and hazardous fast, a confirmed dead ash should be treated as a dead or diseased tree removal and taken down before it starts dropping limbs over a yard, a sidewalk or a neighbor’s property.
Owner-operated since 1991. We make money either way, so our recommendation is based on your tree, not our invoice.
An ISA Certified Arborist assesses your ash and oversees treatment or removal — fully insured.
We treat trees worth saving and handle the full range of tree care and removal for those that aren’t.
If your ash isn’t worth treating, we’ll tell you — and if it is, we’ll say that too.
Based in Brighton, we assess and treat ash trees throughout the 22 communities we serve across Adams, Weld, Jefferson, Boulder, Broomfield and Denver counties.
From the river-bottom neighborhoods around Henderson to the established suburbs of the north metro, if you have an ash tree, we can tell you where it stands with EAB.
Creative Tree & Stump is rated highly across Brighton and the Denver metro, including from ash-tree owners who appreciated a straight answer on whether treatment made sense. Every review is read and answered personally, and the most recent ratings tell you the most about the service you can expect today. Read verified Google reviews on our customer reviews page.
Healthy ash can be treated and protected with trunk-injection insecticide. Removal is the better option once a tree has lost more than roughly 30 to 50% of its canopy or is structurally failing. The earlier you treat, the better the odds — we assess each tree and advise honestly.
We inject emamectin benzoate, a systemic insecticide, directly into the trunk. The tree carries it into the canopy, where it kills the larvae tunneling under the bark — the stage that actually kills ash. One injection typically protects the tree for about two years before the next cycle is due.
About every two years with trunk-injected emamectin benzoate. Because EAB pressure is ongoing, treatment continues for as long as you want to protect the tree — it is a recurring commitment, not a one-time fix.
Watch for thinning and dieback in the upper canopy, D-shaped exit holes in the bark, vertical bark splits, heavy woodpecker activity flaking the bark, and sprouts erupting from the trunk and base. By the time symptoms are obvious the infestation is usually well underway, so an early assessment gives a healthy tree the best chance of being saved.
Yes. It was first confirmed in the state in Boulder in 2013 and has spread across the Front Range, with established populations throughout the Denver metro. CSU Extension and the Colorado State Forest Service track its ongoing spread, and they expect it to keep moving through the region’s ash population.
It depends on the tree’s health, size, location and value to you. A healthy, mature shade ash in a good spot is often worth protecting, since treatment costs less per cycle than removing and replacing a large tree. A declining or poorly placed ash usually is not, and we will say so rather than sell you years of treatment on a tree that should come down.
It is priced by the trunk diameter of the tree and repeated about every two years. A larger tree costs more per treatment. We give a free, transparent estimate and can compare the long-run cost of treating against removing and replanting, so the choice is based on numbers rather than guesswork.
Only to other true ash trees, in the genus Fraxinus — green, white and black ash. It does not attack other species, and mountain ash is not a true ash, so it is not a host. If you have multiple ash, though, they are all at risk, and we can build a treatment plan that covers them together.
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