Emerald Ash Borer

Emerald Ash Borer (EAB) is native to eastern Asia, where it does not pose a problem.

It was accidentally introduced to North America in Detroit via infested pallet wood in 2002. In the United States, EAB will likely kill all native non-treated ash trees.

The first confirmed case of EAB in Minnesota was found in St. Paul in 2009 and it has since spread throughout multiple Minnesota counties. EAB was confirmed in northeast Eden Prairie in April 2017.

All of Hennepin County is under an EAB quarantine regulated by the Minnesota Department of Agriculture (MDA), which means the public cannot transport any hardwood from Hennepin County to a non-quarantined county.

This means you cannot transport ash material or firewood outside of the county. EAB can only spread up to a mile each year on its own. Most of the spread of EAB has been through the transport of infested wood, such as firewood.

Ash Trees on Public Property

More than 3,000 ash trees are on maintained City property — within the right of ways and parks — and more than 2,000 are designated for removal.

New trees representing a diverse pallet of species are being planted at one-and-a-half times the rate of removal. A diverse range of replanted species reduces the potential impact of future invasive species.

A management plan of both treatment and removal of ash trees minimized the impact on the City’s budget for any one year. It also spreads out workloads to a manageable level across 10 years while preserving a portion of the City’s healthy ash trees.

Eden Prairie EAB Management Inventory Map

MN EAB Status Map

If you are concerned about specific trees located on public property, contact the Parks and Natural Resources Division.

Treating EAB

Due to the discovery of EAB in Eden Prairie, the City contracted with Rainbow Treecare to treat public ash trees growing along streets and in parks.

A citywide bulk discount is available through 2026 for Eden Prairie property owners to treat trees at least 10 inches in diameter and in good physical condition. The average cost to treat an ash tree with a 15-inch diameter trunk is about $120 and provides two to three years of protection.

Treatment is typically much cheaper than removal and more environmentally friendly. Schedule a free consultation at rainbowtreecare.com/cities/eden-prairie or call 952-767-6920.

Emerald Ash Borer FAQ
- Can I treat my ash tree myself?
  The City does not recommend treating ash trees yourself. Homeowner treatments typically use neonicotinoids which can be harmful to groundwater and pollinators if improperly applied. Additionally, studies show these treatments are less effective than those done by professionals. Lastly, the state restricts the amount of neonicotinoids that can be applied on a residential parcel. Please contact the Minnesota Department of Agriculture before treating your trees yourself to make sure you are not violating these restrictions.
- Does the City replant trees in residential right of ways?
  The City does not replant trees removed from residential right of ways. Trees are replanted in nearby parks, as this growing environment is most suitable to tree success, and along arterial roads as a tool to slow traffic.
  
  The City encourages residents to replant trees on their property (not in City right of way) to replace canopy cover. The Minnesota Department of Natural Resources provides information on planting location, tree selection, tree care and much more.
- How do I identify an ash tree?
  Minnesota Department of Agriculture's Ash Tree Identification guide [PDF]
  
  You can also upload a photo to the City’s Parks and Natural Resources Division. Include close-ups of the leaves, buds, bark and whole tree, if possible.
- How long do ash trees need to be treated for EAB?
  Emerald ash borer’s (EAB) population is expected to rise and fall in our area over a period of approximately 10 to 15 years.
  
  Ash trees will need to be treated every two to three years (using emamectin benzoate) during this time. After all of the non-treated ash trees have died, EAB's food source will be limited, reducing its population. At that point in time, the intervals necessary between treatments will likely increase to three to six years, depending on pest conditions.
- How safe are EAB treatments?
  There are increasing and well-warranted concerns regarding the over-reliance on pesticides. Neonicotinoids and their effects on pollinators such as bees, and soil-applied products that have the potential to reach storm/ground water, are a concern.
  
  Aligning with the City’s efforts to be a pollinator-friendly community (see Resolution No. 2016-37 Endorsing “Pollinator-Safe” Policies and Procedures) the pesticide emamectin benzoate is not a neonicotinoid. It is a systemic insecticide injected directly into the trunk of a tree, which minimizes its non-target effects, and potential to reach water sources.
  
  Ash trees are wind-pollinated and are not a substantial nectar source for bees. They flower early in the growing season and only for a limited number of days. Emamectin benzoate has a low-toxicity rating for mammals, low bioaccumulation potential within ecosystems and is immobile in soil. This means the insecticide does not build up levels within an ecosystem and is minimally harmful to people and animals.
  
  While there are valid concerns regarding the overuse of pesticides in our environment, those concerns should be aimed at reducing pesticide use where fewer benefits result. The known environmental consequences of losing thousands of ash trees are vastly greater than the minimal risk associated with inoculating ash trees to protect them from certain death.
  
  More information is available on the Emerald Ash Borer Network website.
- Is the tree in my front yard the City's responsibility?
  The City owns a portion of land beyond each street called the right of way. This land is specifically dedicated for public purposes and can include sidewalks, above and below-ground utilities, snow storage and trees that are maintained by the City. Rights of way can vary in size. Many residential streets have 50-foot rights of way, but property owners should review their lot surveys to verify their specific right of way widths and easement distances. Residents should not treat or remove trees on public property. If you are concerned about specific trees located on public property, contact the City's Parks and Natural Resources Division.
- Should all ash trees be treated for EAB?
  Emerald ash borer (EAB) has been shown to kill essentially 100% of ash trees not chemically treated. Although it is recommended to preserve larger, well placed, healthy ash trees, some are not suitable for treatment and should be removed.
  
  It is not recommended to immediately remove all ash trees you do not plan to treat, but you should prepare for it.
  - Start a replacement tree close to the ash you plan to remove
  - If you have multiple ash trees to remove, do so in stages
  - Do not prune or remove a tree during EAB's active period (May-September)
  - It is more expensive to remove a dead tree than a living one, this can be especially true in backyards and hard-to-reach areas
  - Keep a close eye on your ash trees since EAB-infested trees can go from looking a little thin to dead in a year or two
  Contact an ISA-certified arborist if you start to notice a thinning canopy or cracking bark in the upper half of the tree. To find certified arborists in our area, visit treesaregood.org/FindAnArborist.
  
  Do not treat or remove boulevard or park trees. If you are concerned about specific ash trees on public property, contact the City's Parks and Natural Resources Division.
- What is emerald ash borer?
  Emerald ash borer is an insect that kills ash trees and is spread through transported firewood.
  
  The adults are small, iridescent green beetles that live outside of trees during the summer months. The larvae are grub or worm-like and live underneath the bark of ash trees. Trees are killed by the tunneling of the larvae under the tree's bark.
- What should I do if I want to save an ash tree on my property?
  To promote proper EAB treatment on private property, the City has contracted discounted rates with Rainbow Treecare for Eden Prairie property owners.
  
  Through this program, the average cost to treat a 15-inch diameter ash tree is approximately $120, which provides two to three years of protection. This discount is available for ash trees that are at least 10 inches in diameter and in good condition.
  
  Contact Rainbow Treecare at 952-767-6920 for more information and to schedule a free consultation.
  
  The City has ensured Rainbow Treecare meets high standards in staff training, years of experience, and has several commercial pesticide applicators and ISA-certified arborists on staff. Treatment offered through this program is a trunk injection of emamectin benzoate, which offers protection from EAB for two to three years.
  
  Several chemicals on the market have been shown to provide some amount of protection for ash trees against EAB. However, there is a varying amount of chemical exposure, cost and overall protection offered by each product. The use of soil drenches to treat for EAB is highly discouraged.
  
  The City recommends a trunk injection of emamectin benzoate due to its limited chemical exposure and proven effectiveness. Optimal timing of trunk injection is after trees have leafed out in spring, but before EAB eggs have hatched, or generally between mid-May and mid-June.