BROOMFIELD, Colo. – This week, residents of several Front Range communities will notice trees in high-traffic public parks or along street rights-of-way encircled with wide bands of green or yellow ribbon that warn of an invasive tree pest.

City parks departments, Colorado Tree Coalition volunteers and others have marked more than 450 trees, all of which are ash, to offer a visual example of a mere fraction of the millions of trees in Colorado that could be lost to the invasive, tree-killing emerald ash borer (EAB).

National EAB Awareness Week

As part of National EAB Awareness Week, May 17-23, the wrap is intended to help people recognize what ash trees look like, and prompt homeowners and other landowners to consider early management options for EAB. These may include removing unhealthy trees before they die and planting new trees near ash that could ultimately replace trees lost to the pest.

The tree wrap offers the simple message “This ash tree is at risk from Emerald Ash Borer” and directs passers-by to for more information. Communities participating in the awareness week by wrapping ash trees include Broomfield, Englewood, Erie, Lafayette, Lakewood, Longmont, Louisville and Westminster. Many trees also are wrapped on Boulder County properties and on the University of Colorado main campus, and the county is offering EAB information tables at area garden centers.

“The most important thing Front Range communities can do now is exactly what these communities are doing – preparing for emerald ash borer’s arrival by raising EAB awareness, and sharing information about how to identify ash trees and the symptoms of the pest,” said Laura Pottorff, lead representative of the interagency Colorado EAB Response Team,* of which the Colorado State Forest Service is a member.

EAB, a non-native pest responsible for the death of millions of ash trees in 25 states, was confirmed in the City of Boulder in September 2013. The exotic insect has become a concern for communities all over Colorado because each year it can fly up to a half-mile to infest new trees. There also is the ever-present risk of EAB spreading much faster through human transport of firewood and other raw wood. An estimated 15 percent or more of all urban and community trees in the state are ash (genus Fraxinus).

Pottorff, the plant-pest quarantine manager for the Colorado Department of Agriculture, said all the trees wrapped by participating communities this week are green or white ash varietals, and none are known to harbor EAB, which to date has only been confirmed within the City of Boulder.

For more information about ash tree identification, the symptoms of EAB and treatment options, as well as an updated map showing where EAB has been detected in Colorado, go to

*The Colorado EAB Response Team is comprised of members from the following agencies/organizations: Boulder County, City of Boulder, Colorado Department of Agriculture, Colorado State Forest Service, Colorado State University Extension, Colorado Tree Coalition, Green Industries of Colorado, University of Colorado and USDA Animal and Plant Health Inspection Service.

EAB: What Coloradans Need to Know

  • Learn how to identify ash trees, and signs of EAB infestation in ash trees:
    • thinning of leaves and upper branches and twigs
    • serpentine tunnels produced by larvae under the bark
    • D-shaped exit holes 1/8-inch wide
    • new sprouts on the lower trunk or lower branches
    • vertical splits in the bark
    • increased woodpecker activity
  • Multiple EAB management strategies exist for homeowners and communities, including monitoring trees for the early presence of the pest, removing and/or replacing ash trees, protecting trees with insecticides and planting new trees nearby in an effort to get them established before the arrival of EAB. The closer ash trees are to an area of known EAB infestation, the higher the risk that they will become infested.
  • If hiring someone to apply pesticide treatments to protect ash trees, the applicator must be licensed by the Colorado Department of Agriculture as a Commercial Pesticide Applicator.
  • Never transport firewood or other products from ash trees, as this is the most likely method of accidental spread. A quarantine is now in place in Boulder County and surrounding areas to try and prevent the human-assisted spread of EAB.

Learn More

For current information about EAB in Colorado, including the current quarantine in Boulder County and surrounding areas, go to If you think you have EAB in your ash trees, please contact the Colorado Department of Agriculture at 888-248-5535 or email