The emerald ash borer (EAB) was discovered in Boulder County in September 2013. This created great concern in Colorado because the EAB is responsible for the deaths of tens of millions of ash trees in the eastern half of the U.S. Ash trees make up about 15 percent of the urban tree forest in the Colorado front range. The Denver Metro Area alone has over 1.4 million ash trees. The idea of all those ash trees dying gets peoples’ attention.
Denver property owners can keep informed about the EAB by visiting the Colorado Department of Agriculture emerald ash borer website. The latest Ash Management Zone Map, shows where the EAB infestations are located in Colorado. The EAB is now in Superior which is half way between Boulder and Denver.
How to Interpret the Ash Management Zone Map
Zone 1 – Presumed Infested
Ash trees in Boulder are presumed infested with the emerald ash borer. Homeowners should get their ash trees inspected by a certified arborist. High value ash trees not infected by the EAB can be treated by chemical treatment. EAB treatment options should be discussed with the arborist. If it is decided that trees should be cut down and removed, please do not share this wood with anyone. Ash wood should be removed according to the disposal requirements of the Boulder County EAB quarantine.
Zone 2 – EAB Quarantine
Homeowners in Boulder County who want to protect high value trees should get their trees treated. The rule of thumb is mature ash trees within 10 miles of any EAB infestation should get treated. The DLC website and blog are good sources of information about EAB identification and treatment.
Zone 3 – EAB Planning
The average value of a landscape with mature trees is about 5 to 10 percent of the market price of the home. The average home value in Denver went over $400,000 for the first time in 2015. This means a mature urban landscape is worth between $20,000 and $40,000. If the yard ash trees are valuable to a homeowner, they should be treated immediately.
Between Fort Collins and Castle Rock there are roughly 2 million ash trees. There will be a rush to get their ash trees treated by homeowners if the EAB moves out of Boulder County. The demand for EAB treatment will overwhelm local front range tree service companies. Homeowners with mature ash trees need to decide if they should gamble that the EAB stays put in Boulder or would it be more prudent to treat them now and avoid the rush.