Emerald Ash Bore in Denver

🪲 Emerald Ash Borer in Denver: What Homeowners Need to Know

Protect Your Ash Trees with Help from Colorado Premier Tree Care

The Emerald Ash Borer (EAB)—one of the most destructive invasive pests in North America—has officially reached Congress Park in Denver, Colorado as of late June 2025. This marks a major development in the spread of this invasive beetle throughout the Denver Metro area, threatening tens of thousands of mature ash trees in both residential and commercial landscapes.

As a trusted Denver tree service provider, Colorado Premier Tree Care is here to help property owners understand the threat EAB poses—and how to protect their trees.

🌍 A Brief History of the Emerald Ash Borer

The Emerald Ash Borer (Agrilus planipennis) is native to eastern Asia. It was first detected in the United States near Detroit, Michigan in 2002. Since then, it has killed over 100 million ash trees in more than 30 states and parts of Canada.

EAB larvae tunnel beneath the bark of ash trees, cutting off the tree’s ability to transport water and nutrients. Infested trees usually die within 2–4 years of the initial attack if left untreated.

In Colorado, EAB was first found in Boulder in 2013. It spread slowly but steadily, reaching areas such as Broomfield, Arvada, Lakewood, and Westminster. Now, its detection in Denver’s Congress Park neighborhood signals that it has fully arrived in the city.

🌳 Why This Matters for Denver Tree Owners

Denver has an estimated 330,000 ash trees, making up roughly 1 in 6 trees in the urban forest. Many are located on residential properties, business landscapes, and public rights-of-way.

Without proactive care, most untreated ash trees will die from EAB.

The cost of removing a large, dead ash tree can be thousands of dollars—far more expensive than preventative treatment.

💉 How to Protect Your Ash Trees from EAB

At Colorado Premier Tree Care, our ISA-certified arborists offer professional emerald ash borer treatment servicesusing Mectinite® (emamectin benzoate)—a highly effective injectable pesticide that protects your trees for up to two years.

Our EAB Protection Program Includes:

• On-site assessment of your ash trees

• Trunk injection with systemic insecticide

• Monitoring and follow-up care

• Guidance on whether removal or preservation is best for each tree

🌿 Timing is key: The best time to treat is late spring to early summer, while trees are actively transpiring.

🔍 Signs of Emerald Ash Borer Infestation

If you're unsure whether your ash tree is at risk, watch for these symptoms:

• D-shaped exit holes in the bark (1/8” wide)

• S-shaped tunnels under bark layers

• Bark splitting or flaking

• Thinning canopy and dieback

• Increased woodpecker activity

Even if you don’t see visible damage, preventative treatment is still recommended—especially now that EAB has been found in Congress Park and surrounding Denver neighborhoods.

📍 Serving the Denver Metro Area Since 2017

At Colorado Premier Tree Care, we’ve proudly served homeowners and businesses in Denver and surrounding areas since 2017. Our certified arborists specialize in:

• Tree diagnosis and treatment

• Emerald ash borer control

• Tree fertilization and soil health

• Tree pruning and removals

• Risk assessments and consultations

We offer tree services throughout the Denver Metro, including Congress Park, Capitol Hill, Park Hill, Wash Park, Cherry Creek, and surrounding communities.

🛡️ Don’t Wait Until It’s Too Late

The Emerald Ash Borer has arrived in Denver—and it’s not going away. If you have ash trees on your property, the time to act is now.

Contact Colorado Premier Tree Care today to schedule a free EAB inspection and learn how we can help preserve the value, beauty, and safety of your trees.