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City prepares Denver residents to battle destructive emerald ash borer

Mayor Michael B. Hancock urges Denver residents to "Be A Smart Ash" and join the city in saving Denver's ash tree population from Emerald Ash Borer infestation.
Mayor Michael B. Hancock urges Denver residents to “Be A Smart Ash” and join the city in saving Denver’s ash tree population from Emerald Ash Borer infestation.

DENVER — Denver’s City Forester is encouraging Denver residents to embrace their inner Smart Ash and join the Be A Smart Ash movement, a campaign launched May 2 in preparation for the inevitable arrival of the Emerald Ash Borer (EAB), a metallic-green insect that destroys ash trees.

The flying pest, which was discovered in Boulder in September 2013, hasn’t yet been detected in Denver. However, one in six trees in the City and County of Denver is an ash tree, so it’s vital that residents understand how they can save their ash trees and protect the city’s urban forest.

Residents can become Smart Ashes by visiting for valuable resources such as how to identify ash trees, signs of EAB infestation, and resources to help residents take action by treating or removing ash trees on their property.

“The Emerald Ash Borer could have a devastating impact on Denver’s tree canopy,” Denver Mayor Michael B. Hancock said. “The infestation has the potential to cause damage comparable to the destruction caused by the pine beetle in Colorado’s high country a few years ago. Let’s work together to battle the Emerald Ash Borer and protect our beautiful urban forests.”

The EAB has devastated ash tree populations in 25 states and parts of Canada, costing communities there billions of dollars. Based on this widespread destruction, the Denver City Forester has been proactively planning to battle the EAB for the past several years.

While the EAB has wings, it typically doesn’t travel more than a half-mile from its emergence tree. Most long-distance travel of the EAB has been traced to human movement of ash tree firewood or nursery stock. Movement of other untreated ash wood and wood chips greater than one inch also presents a risk.

The Office of the City Forester, a division of Denver Parks and Recreation, will care for ash trees on city property, including parks; however, residents are responsible for caring for ash trees on private property. Properly administered treatments are 90 percent effective and tree removal and replacement can be dangerous work, so it’s highly recommended to work with a reputable tree care professional no matter which course of action residents choose to take in battling EAB.

“The City has been anticipating the Emerald Ash Borer’s arrival in Denver and working to reduce its impact,” Parks and Recreation Executive Director Happy Haynes said. “We’re advising Denver residents to Be A Smart Ash, not just because we need to heighten awareness, but also because we need community support. Through this campaign, we strive to give residents the information they need to be part of a movement that will have a significant and long-term impact.”

According to the City Forester, Denver will replace small ash trees on city-maintained land, and a rigorous treatment schedule is in place for some of the historic ash trees on city property. Additionally, 3,800 non-ash trees will be planted by the City this year alone, because planting diverse species now will decrease gaps caused by ash tree losses. Denver residents who have room in the public right-of-way next to their property may be eligible for a free replacement tree. Applications can be found

About Be A Smart Ash

Be A Smart Ash is a public education campaign brought to you by your friendly City Forester, an office within Denver Parks & Recreation. The Be A Smart Ash campaign aims to school up residents in the City and County of Denver on the EAB’s attempt to run amok. The goal? To encourage residents to be smart about their ashes — take action, identify ash trees and (when necessary) treat or replace them. For more information on the Emerald Ash Borer and to learn how to Be A Smart Ash, visit or follow us on Twitter at @BeASmartAsh.

Denver Parks and Recreation (DPR) facilities are unrivaled in the Rocky Mountain West. The DPR system spans over a 148-year history, from the first park created in 1868 to nearly 20,000 acres of urban parks and mountain parkland today. For more information, visit, Check us out on YouTube, like us on Facebook and follow us on Twitter.