Prepare for EAB in Your Yard
The first step is to determine if you have ash trees on your property (PDF), and then decide which ash trees you would like to protect or remove.
Ash trees can be protected with a chemical treatment. Treatment can happen as a preventative measure before trees are infested with EAB or if the infestation is caught in the early stage. By the time ash trees show the signs and symptoms of EAB such as woodpecker activity, bark splits and crown dieback, treatment may not be an effective option. Trees showing more than 30 percent crown decline are not good candidates for treatment. Consider treating ash trees that are larger than 10” in diameter and in good physical condition.
Treatments are injected at the base of the trunk and trees must be re-treated every two years. The cost is based on the size of the tree to be treated and the overall number of trees being treated on the property. This is an ongoing cost, but it can be more cost-effective over the long term versus the cost of removing and replacing the tree. Recent research has indicated you can protect a tree for 20 years for the cost it would take to remove and replace an ash tree. Treatment has the added benefit of protecting and preserving ash trees that provide numerous benefits to homeowners and the community.
The City has created an Ash Tree Injection Program which provides a discounted rate to residents to treat private property ash trees by a City contractor. This program has ended for the 2019 season but it will be offered again in May 2020 for homeowners who want to protect their ash trees from EAB.
Tree companies can help protect your ash trees but be sure they are a licensed pesticide applicator. The Minnesota Department of Agriculture's website can help you determine the best tree care company for you.
If you opt to treat the trees yourself, be aware that the available chemical treatments at garden centers are not concentrated enough to protect an ash tree with a trunk diameter greater than 15” (48” circumference). Soil-applied insecticides can get taken up by nearby flowering plants and kill pollinators. In addition, soil applied treatments should not be used within 25 feet of a storm drain or water resource such as a wetland, creek or lake.
In order to preserve established trees that contribute to the community’s canopy, the City injects ash trees in parks and boulevards (right-of-way easements). Ash trees that are in good/fair condition that are greater than 10 inches in stem diameter are the prime candidates.
Check the City’s interactive Ash Tree Injection map to see if your boulevard tree is planned for protection. Zoom in for more detail or click on the globe icon to enter an address. Each red dot indicates that tree has been injected or is planned for injection. If you think you have an ash in the boulevard that merits protection, call 952-985-2726.
Ash trees that are not treated will eventually die from EAB. Consider removing ash trees that are smaller than 10” in trunk diameter or that are in poor physical condition. Removing trees can be done preemptively or after a tree is infested. However, EAB infested ash trees become brittle and hazardous, which can increase the cost of removal. Plan the removal between October 1 to May 1 when the adult beetles are not active. Ash trees that are showing signs and symptoms of infestation will be marked by the City each winter so homeowners can remove them ideally before they become hazardous.
Curious about where EAB has already been found in Lakeville? The Minnesota Department of Agriculture (MDA) hosts an interactive map that tracks where EAB has been found throughout the state. In many instances, it is not a “tree-for-tree” designation but a pin dropped in a neighborhood where EAB has been confirmed. The City will continue to add to this map when they mark infested trees each winter so residents can see where it has been confirmed.
For ash trees being treated, proper pruning can increase the overall health and condition of a tree. Ash trees normally produce a lot of dead wood in the lower canopy of the tree even when they are in good health. It is recommended that ash trees be pruned between October 1 and May 1 when EAB is dormant and there is a reduced risk of transporting the pest in the wood waste.
Visit our "How to Hire a Tree Contractor" webpage for more information.
Replace ash trees that were removed and start diversifying the species of trees on your property. The City’s Annual Tree and Shrub Sale, held each spring, is a great way to add trees to your yard.
There is a federal and state quarantine on counties in Minnesota with infested ash trees. Dakota County is under quarantine. The quarantine restricts the movement of ash wood material and all hardwood firewood. For more on the quarantine and for ash wood disposal sites, check the Minnesota Department of Agriculture’s website.
Additional links to help you plan: