Aurora is dealing with an infestation of Emerald Ash Borers, a parasitic insect that kills Ash trees and will cost the city about $10,000 to manage. 

City Forester Adrian Camacho encouraged city residents with Ash trees on their properties to either treat or replace them, he said in a Monday evening study session.

Ash borers were initially found in Boulder in 2013 and have spread across the Front Range since. In June, they were confirmed in Aurora, according to the city’s website. 

Aurora’s forestry department has been working to mitigate the issue since 2015, Camacho said, reducing the city’s Ash tree population from 7,000 to almost 5,000 in that time. The efforts have made the issue now more manageable, Camacho said.

The city’s forestry team is choosing to treat about 50 of Aurora’s city-owned Ash trees, of which there are almost 5,000, and replace many others, Camacho said. 

Treating trees is expensive and treated trees still die eventually, he said, so replacing the trees is more effective. One of the trees the team has chosen to treat is the oldest city-owned tree, which happens to be an Ash tree, Camacho said.

In total, the City of Aurora has 110,500 Ash trees, according to Camacho. Of those, almost 5,000 are city-owned.

The forestry team’s plan includes replacing some city-owned ash trees, treating others and encouraging private residents to do the same, according to council documents. Staff have set aside $10,000 for treatment.

Forestry officials urged Aurora residents to address the Ash trees on their properties as well, adding that addressing them early is the cheapest and easiest option. The more trees degrade, the harder and less safe they are to remove, Camacho said.

He shared several traits of Ash trees to help people identify whether or not they have the trees on their property. Traits include opposite branching, compound leaves, diamond-pattern bark,

Some signs of infestation include thinning canopy, epicormic growth and suckering from roots, he said.

“If you have an Ash tree please think about replacing it and if you don’t want to replace it, treat it,” Camacho said. 

Aurora residents can check whether their trees are city-managed or privately owned on the City Trees map available through the city’s website.