Emerald ash borer (EAB) is an insect that attacks and kills all species of ash trees. The adults are small, green beetles that live outside of trees during the summer months. The adults lay their eggs on branches and in bark crevices. The eggs hatch into larvae, which tunnel underneath the bark to feed. As the tree becomes infested with EAB larvae, it begins to decline in health and die.
The Minnesota Department of Agriculture (MDA) has imposed a quarantine for several counties, including Washington County, prohibiting the movement of potentially infested items such as ash limbs, branches, and logs out of those counties.
The Woodbury Forestry Division began implementing various EAB management practices since the pest was first detected in Minnesota in 2009. This includes inspecting hundreds of ash trees on public land, removal of low priority ash trees in parks and in boulevard areas, and the installation of replacement trees on public land where appropriate.
In August 2017, infected ash trees were discovered in the parking lot of the Woodbury movie theater, located off Queens Drive.
Ash trees in Woodbury
Ash trees are numerous on both public and private property in Woodbury. As of May 2011, all species of ash made up 17 percent of the Woodbury inventory of park and boulevard trees, and green ash is the most common species in the inventory. Ash numbers are high particularly in the older neighborhoods of Woodbury such as Park Hills, Woodbury Heights and Royal Oaks, but have been planted extensively in newer developments as well.
The city has an EAB Preparedness and Management Plan in place. The plan includes public outreach; updates to policy and ordinance, including the addition of EAB to the Environmental Management Ordinance; and a strategy for removal of ash trees on public lands.
What can residents do?
Residents are encouraged to take steps to mitigate the effects of the expected tree loss across the city as well as be on the lookout for signs and symptoms of EAB infestation. Here is what you can do:
- Determine if you have ash trees on your property. Look for signs of EAB damage, which include dieback of leaves in the upper one-third of the tree's branches, heavy woodpecker activity, bark splitting, S-shaped larvae tunnels under the bark, or a significant amount of water sprouts on the trunk. If you suspect an EAB infestation, please call a certified tree service provider.
- DO NOT plant new ash trees.
- Consider removal of declining or small ash trees on your property now, especially if they are small enough to do the removal yourself. This may save on the cost of removal in the future. Keep in mind that most trees will require a professional to remove.
To prevent the accelerated spread of adult beetles, MDA guidelines recommend pruning and removal of ash during the months of October through April when the EAB is dormant. If possible, avoid pruning and removal of ash trees during the months of May through September, when the EAB is active.
Trees can be disposed of at the Woodbury compost site; disposal fees are charged. Call Composting Concepts at (651) 436-1213 for more information. Tree removal companies usually will dispose of the tree for you. In order to prevent the spread of EAB, all ash wood should be properly destroyed within Woodbury.
- Early detection and preventive treatments with approved insecticides can prolong the life of an ash tree. Tree contractors with pesticide applicators licenses should be consulted to discuss treatment options. Before deciding to treat your tree, educate yourself about the pros and cons of these chemicals. The city recommends the trunk injection application method; the soil drench application method has a higher risk for unwanted environmental effects. Keep in mind that there is no “cure” for EAB infestation and insecticide treatments will be needed every one to three years, depending on the chemical used. Hire a certified arborist with a pesticide applicator’s license to perform these treatments.
- Do not remove or treat ash trees in the public right-of-way near the street (boulevard trees), as these may be managed by the city in some areas. Woodbury Heights, Park Hills and Royal Oaks are the neighborhoods where boulevard trees are most likely city trees. Call the Public Works Department at (651) 714-3720 if you have questions.
EAB resources for residents
- Signs and Symptoms of EAB Infestation
- Homeowner Guide to Insecticide Selection, Use, and Environmental Protection
- Hire a certified arborist
- Questions and Answers about EAB Quarantine and Compliance Agreements
- Minnesota Department of Agriculture "Got Firewood - What you need to know"