The City of Rochester's Forestry Division is making a proactive effort to protect Rochester’s urban forest from an invasive species called the Emerald Ash Borer.
What is the Emerald Ash Borer?
The Emerald Ash Borer (EAB) is an exotic beetle that was imported accidentally into the United States on packing material that originated in Asia. EAB larvae feeds on the inner bark of ash trees, disrupting the tree's ability to transport water and nutrients. The EAB has already killed tens of millions of trees in the states where it has been detected. Other than New York, the beetle has been detected in 12 other states including Illinois, Indiana, Kentucky, Maryland, Michigan, Minnesota, Missouri, Ohio, Pennsylvania, Virginia, West Virginia, and Wisconsin.
Has the Emerald Ash Borer been detected in the City of Rochester?
Forestry Division personnel have discovered the EAB in and around Upper Falls Park on St. Paul Street in Downtown Rochester. As of June 2011, seventeen ash trees in the area appear to be infested and one of them has died. The EAB was detected in other parts of Monroe County (specifically, Scottsville) in 2010. Working closely with federal and state agencies, the City's Forestry Division has set up traps in ash trees throughout the city that can detect the EAB.
Has Rochester done an inventory of its ash trees?
There are approximately 5,000 ash trees in the City of Rochester's right of way (this includes the tree lawn in between the sidewalk and curb, parks, cemeteries, etc). These trees make up approximately 8% of all City-owned trees. International Society of Arboriculture-certified arborists have performed a condition rating of the 5,000 ash trees in the City's right-of-way. Condition ratings are based on overall health and structure of the trees.
How is Rochester treating ash trees that are in good condition?
City Forestry crews are treating ash trees that are in good condition with an insecticide called "TREE-age." Forestry crews will inject TREE-age directly into the tree’s vascular system through several 
plugs that seal it inside the tree. When finished, crews will post small signs around the tree indicating that treatment has occurred. These signs should remain for 24-hours after the treatment. This treatment is expected to protect the tree for a period of two to three years, at which point it may be eligible for another treatment. Eventually the tree will have to be replaced with one of a different species.
Where have ash trees been treated so far?
How is Rochester treating ash trees that are in poor condition?
Because the ash trees in the poorest condition will be most vulnerable the EAB's effects, the Forestry Division has identified 300 of the trees as candidates for removal in anticipation of their infestation. First, all "poor" condition trees (172) will be removed. Next, 128 "fair" condition trees will be removed. "Fair" condition trees on streets with a high concentration of ash trees were targeted for removal before other "fair" condition trees so that some neighborhoods will not be stripped of their entire tree population if the EAB were to arrive.
Will ash trees that are removed be replaced?
Yes. All ash trees that are removed will be replaced with a more appropriate species, unless an owner objects to having a new tree planted. Property owners will be notified if the City is planning to remove a tree near their property.
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What should I do if I still have questions?
If you have additional questions or suspect that an ash tree is dying, you can call 311 (outside of the city, call 585-428-5990) or call the Forestry division at (585) 428-7581.