Knowledge Base

Emerald Ash Borer (EAB) was first discovered in the Rochester area in August 2014 and confirmed within city limits in 2015. As a result, Olmsted County was added to the Minnesota EAB quarantine area.

The City of Rochester Parks & Recreation Forestry Division manages a comprehensive urban tree program, including efforts to monitor, manage and control EAB.

Why This Matters

• Rochester's current tree canopy cover is 27%
• The Society of American Foresters recommends cities maintain a canopy cover of 40-60% at a minimum.
• There are approximately 4,000 inventoried ash trees in Rochester.
• If every ash tree in Rochester were removed due to EAB, canopy cover would drop to 19.5%

Our Priority

Ash trees make up a significant portion of Rochester’s urban forest. With 4,000 inventoried ash trees at risk, evaluating and managing this invasive pest is a top priority. Protecting existing trees where possible and planning for strategic removals and replacements are essential to maintaining environmental health, neighborhood livability and long-term sustainability.

For more information on Emerald Ash Borer (EAB), visit:

Emerald Ash Borer | City of Rochester