Emerald Ash Borer

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The Emerald Ash Borer (EAB) is a destructive and invasive wood-boring beetle that, in the early 2000’s, was imported accidentally into the United States on wood packing material that originated in Asia. EAB larvae feed on the inner bark of ash trees, disrupting the tree's ability to transport water and nutrients.  EAB has killed millions of ash trees in North America.

In 2009, EAB spread to Minnesota, and the Minnesota Department of Agriculture ratified a quarantine area of a number of Minnesota counties, including Hennepin, that placed restrictions on the use, movement and transport of ash wood material.

In January 2017, the City of Maple Grove received confirmation from the Minnesota Department of Agriculture that EAB was present in Maple Grove.  View this short video about EAB in Maple Grove.

Where in Maple Grove has EAB been found
Please visit the interactive map to view the most up-to-date information on confirmed locations within Maple Grove.

How to identify if you have an Ash tree on your property
The following website may help in determining the characteristics and providing images of Ash trees.  How to Identify an Ash Tree (pdf) (Minnesota Department of Agriculture) 

What is the life cycle of EAB
Research shows that EAB can have a one to two year life cycle.  Adults begin emerging in mid to late May, with peak emergence in late June.  Females will begin laying eggs about two weeks after emerging.  Eggs hatch one to 2 weeks and bore themselves through the bark and between the bark and wood, where nutrient levels are high.  The larvae feed under the bark for several weeks, typically from late July through October.  The larvae reach full size of 1 to 1.25 inches long.  It is very rare that an adult EAB will be sighted.  Therefore, we encourage residents to look for signs and damage rather than the actual beetle itself. 


What are the signs of EAB

Signs can include D-shaped exit holes in the bark, vertical cracks or splits in the bark, and suckers growing on the tree trunk.  One of the most noticeable signs is woodpecker damage. Winter is an optimal time for viewing infestation and then determining next steps for spring.

 What to do next if EAB has been confirmed on your Ash tree
Trees on private property are the responsibility of the property owner.  If you suspect or have confirmed an EAB infestation, please contact the City of Maple Grove’s Engineering Department at 763-494-6350.

Treatment options or removal of tree

City Code requires infested or diseased tree(s) be removed or effectively treated to prevent the possible spread of EAB.

Treatment:  Treatment can only be done if the infestation is in the early stage or as a preventative measure.  Typically a tree that has EAB will need to be treated on an annual basis for the remainder of the tree's life.  Most often, any treatment options or preventive applications must be done in the springIf you decide to treat your infected tree or have questions about treatment, please contact Kelly at 763-494-6365 or

  You have two options for removal:

  •  Hire and pay for a contractor to remove the tree
  •  Remove the tree yourself

The best time of year to remove an EAB infested tree is between October 1 and May 1, since this is the period when EAB are generally considered dormant.

If a resident chooses to remove the EAB infested trees themselves, they must do so in a safe manner.  Please note that it is against the law to move entire ash trees, firewood from hardwood trees, limbs, branches, ash logs, untreated ash lumber, uncomposted ash chips and uncomposted ash bark chips greater than 1 inch in two dimensions out of EAB-quarantined counties.  Map of quarantine counties in Minnesota.

What is the City of Maple Grove doing
The City of Maple Grove has been preparing for the arrival of EAB for several years. In 2013, the City established a Tree Inventory Program as a foresight to the potential problems our urban forest could possibly come to expect from invasive pests, not just the Emerald Ash Borer.  Through this program, numerous volunteers have donated hundreds of hours to identifying and inventorying the types, sizes and condition of more than 30,000 trees on residential and business properties.  In 2015, City staff began working on a management plan to minimize the spread of EAB once it was discovered in neighboring cities.  In 2016, the City adopted the Emerald Ash Borer Management Plan that established guidelines to minimize the effects of EAB by treating or removing infested trees.  In 2017, the City Council adopted an amended Shade Tree Ordinance that addresses the mitigation of EAB.

The City of Maple Grove will continue to educate residents about EAB and what it will do to a community.  The City newsletter, website (, social media (Facebook/Twitter), and letters to residents are the primary communication pieces for outreach.

City staff will also continue to work with the Minnesota Department of Agriculture, attend forum discussions on EAB, and work with neighboring communities to make sure that the EAB Management Plan being implemented makes sense for the City and its residents. 

Boulevard Trees
Public trees, including those on the boulevard and city parks, are under the care and responsibility of the City. Trees will either be treated or removed depending on various considerations such as the age, health, and location of the tree.

Other Helpful Links
Emerald Ash Borer Program (Minnesota Department of Agriculture)

EAB Status Map (Minnesota Department of Agriculture)
Emerald Ash Borer (Minnesota Department of Natural Resources)
Mistaken Identity - Minnesota Insects Often Confused with EAB (Minnesota Department of Natural Resources)