The Minnesota Department of Agriculture (MDA) has confirmed the first emerald ash borer (EAB) detection in Woodbury. EAB 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.
It was first found in Minnesota in 2009. Since that the time, the MDA quarantined 13 counties in the state, including Washington County, to prevent the spread of EAB. A quarantine prohibits the movement of potentially infested items such as ash limbs, branches, and logs out of those counties, reducing the risk of further spreading the tree-killing insect. The invasive insect has now killed tens of millions of ash trees in 30 states.
The Woodbury Forestry Division began implementing various EAB management practices since the pest was first detected in Minnesota. This includes inspecting hundreds of ash trees on public land, removing low priority ash trees in parks and in boulevard areas, and planting replacement trees on public land where appropriate.
Residents may be tempted to take firewood from within Woodbury and transport it to cabins and camp sites outside the quarantine. The city wants to stress that firewood should not be moved.
The infestation was discovered by a private tree service employee in the parking lot of the Woodbury movie theater. The city notified the MDA of a possible EAB infestation and staff were able to verify the infested trees.
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 are some tips:
- 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, first review the links available on the city's website, and then discuss removal or treatment options with a certified tree care company.
- 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, the 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) 769-0531 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.
The city is planning a public meeting about managing EAB in spring 2018. Details will be announced in the City Update newsletter, on the city’s website, via the city’s InTouch email notification system, through the city’s cable TV programming and on the city’s social media accounts.
Much more information about EAB is available on the MDA website.