The Minnesota Department of Agriculture has alerted the city of Chanhassen that emerald ash borer (EAB) was discovered in an ash tree located inside city limits, according to a city press release. The department discovered the infestation after finding woodpecker damage, bark cracks and telltale S-shaped tunnels under the bark.

Around 20% of the public trees in the city of Chanhassen are ash. That percentage is higher for the private trees in town, with some yards having nearly 100% ash trees. The city strongly encourages residents to educate themselves about EAB and help slow its spread.

The ash borer was first found in Carver County last fall, and the county was placed under quarantine on Nov. 30. There are now 25 counties in Minnesota with EAB.

This is a good time of year to detect signs of emerald ash borer because tree limbs are bare and can be easily seen, according to the city.

When checking for emerald ash borer:

  • Be sure you’ve identified an ash tree, since EAB only feeds on ash trees. Ash have opposite branching — meaning branches come off the trunk directly across from each other. On older trees, the bark is in a tight, diamond-shaped pattern; younger trees have relatively smooth bark.
  • Look for woodpecker damage. Woodpeckers like EAB larvae and woodpecker holes may indicate the presence of EAB. Use binoculars to look high into the canopy
  • Check for bark cracks. EAB larvae tunneling under the bark can cause the bark to split open, revealing the larval (S-shaped) tunnels underneath.
  • Contact a professional. Tree professionals that are licensed by the MDA are educated in the proper identification and handling of ash trees. For a list of these contractors visit:

Emerald ash borer larvae kill ash trees by tunneling under the bark and feeding on the part of the tree that moves nutrients up and down the trunk. Minnesota is highly susceptible to the destruction caused by this invasive insect because the state has approximately one billion ash trees — the most of any state in the nation.

The biggest risk of spreading EAB comes from people unknowingly moving firewood or other ash products harboring larvae. There are three easy steps residents can take to keep EAB from spreading:

  • Don’t transport firewood. Buy firewood locally from approved vendors, and burn it where you buy it.
  • Be aware of the quarantine restrictions. If you live in a quarantined county like Carver County, be aware of the restrictions on movement of products such as ash trees, wood chips, and firewood..
  • Watch your ash trees for infestation. If you think your ash tree is infested, go to and use the guide “Does my tree have emerald ash borer?”

For additional information concerning EAB management, visit

Community Editor

Mark Olson, the Chaska and Chanhassen community editor who has worked in Carver County for 20 years, makes any excuse to write about local history. In his spare time, Mark enjoys perusing old books, watching blockbusters and taking Midwest road trips.