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City of New HopeMinnesota

Emerald Ash Borer Mitigation

Emerald Ash Borer Mitigation
Posted on 05/02/2022


The emerald ash borer (EAB) is an invasive species of beetle first discovered in Minnesota in 2009. The beetle has killed tens of millions of ash trees across the eastern half of the United States and Canada. The EAB beetle lays eggs between layers of bark in ash trees. When larvae hatch, they feed on the ash tree's inner bark, destroying its circulatory system for transporting food and water. Although the actual time it takes for an ash tree to die from EAB will vary based on the size of the tree and the severity of the infestation, on average it takes 2-5 years.

The City of New Hope implemented an emerald ash borer program in 2010 to preemptively address the infestation by removing and replacing public ash trees. The program aims to protect, maintain and enhance the city's urban forest while mitigating the EAB infestation. Since the program's inception, the city has removed more than 800 ash trees from city boulevards and other public lands and funded or partially funded the replanting of more than 300 trees.

Unfortunately, the EAB has made its way to many parts of the metro area, including New Hope. Adult beetles emerge in mid-to-late May. Removing infected trees before adult beetles emerge, helps reduce the infestation of new trees. The City has been working diligently to identify infested trees from city parks and public lands, including boulevards. City crews have been identifying and removing infested trees from city parks while the hired contractor has been removing infested boulevard trees. Under New Hope's Emerald Ash Borer Program, residents who have a boulevard ash tree removed may select a replacement tree from a list of tree species native to Minnesota, free of charge.

Removal of private ash trees infested with the Emerald Ash Borer is the sole responsibility of the property owner. City staff, licensed under the Minnesota Department of Agriculture, can condemn infested ash trees. Once notified by the city, property owners have a defined amount of time to remove private trees according to city code. If the property fails to remove the infested trees within the given timeline, the city's hired contractor will be authorized to remove the tree at the property owner's expense.

Does my tree have emerald ash borer?
Infested ash trees may show one or more of the following symptoms.

  • Increased Woodpecker Activity/Damage: Many species of woodpeckers feed on EAB larvae, pecking the tree's outer bark while foraging and creating large holes when extracting insects.
  • Canopy Dieback: A significant number of dead branches at the top of an ash tree may indicate EAB. It typically begins in the top one-third of the canopy and progresses until the tree is bare.
  • Epicormic Shoots: Tree sprouts growing from the roots and trunk with larger leaves than normal.
  • Bark Splitting: EAB larvae tunneling under the tree's bark can cause the bark to split open, creating cracks in the bark and exposing S-shaped larva tunnels underneath.
  • S-Shaped Galleries: The distinct S-shaped galleries under the bark indicate the presence of EAB.

Help stop the spread
Firewood is one of the most significant contributors to the spread of EAB. Help stop the spread of EAB and other invasive species by taking the following steps.

  • Purchase MDA/USDA certified heat-treated firewood. Certified firewood carries the lowest risk of transporting pests.
  • Buy firewood close to where it will be burned – the more local the wood is, the less likely it is to contain an invasive species not already in the area.
  • Don't store firewood for long periods.

Emerald Ash Borer and any other tree issues should be reported to New Hope Public Works at 763.592.6777 or reported online at Learn more about the forestry and emerald ash borer programs at

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