Bur oak blight

Bur oak blight (BOB) is a fungal leaf disease that affects bur oak trees. The symptoms of BOB are similar to oak wilt disease, with a lot of brown leaves appearing in a tree’s crown and falling off during the latter half of summer, typically late to mid-July. BOB tends to be most prevalent during growing seasons that start out cool and wet. It is rare that BOB would kill an oak tree, but successive years of BOB infestation can result in tree decline.

For management options, contact a St. Louis Park-licensed tree service or the city’s natural resources division.

Dutch elm disease

Dutch elm disease is caused by an invasive fungus and affects all elms native to Minnesota. Symptoms of infected trees include wilting of one or more of the upper branches (leaves on these branches turn brown, wilt and eventually fall off) and brown staining of the wood immediately under the bark (in healthy trees, the sapwood is milky white).

This disease can be managed with preventive fungicide treatments every three years. Arbotect 20-S is the most effective fungicide treatment against DED.

Learn more about Dutch elm disease.

Emerald ash borer

The emerald ash borer (EAB) is an invasive beetle that kills all untreated ash trees (except mountain ash) Trees heavily infested with EAB can become brittle quickly and must be removed as soon as possible. Delayed removals may increase removal costs.

Discounts are available to residents for treatment. The city also has a program to assist income-qualified residents with ash tree removal and treatment costs. View the emerald ash borer page to learn more about EAB treatment options and assistance programs

Oak wilt disease

Oak wilt disease is caused by an invasive fungus, A tree infected with oak wilt will have leaf discoloration, which begins at the outer edge of the leaf and progresses inward. Leaves turn a dull green, bronze or tan color, and eventually turn brown and shrivel.

Oak wilt is transmitted from tree to tree primarily by sap-feeding beetles attracted to freshly wounded oak trees. These beetles are typically active April through October. Don’t prune oak trees during this time to avoid spreading infection. Oak wilt is also transmitted through root grafts of other oak trees.

If you feel your tree or a nearby oak tree is infected with this disease, contact the natural resources division or a city-licensed tree care company for management options.

Two-lined chestnut borer

Two-lined chestnut borer is a native insect that attacks weakened or stressed oak trees. This insect is not a threat to healthy oak trees. Oaks that are weakened due to drought, construction activities or disease are susceptible to the two-lined chestnut borer. Infected trees typically die two to three years after infestation.

View the oak tree management and care page to learn more about keeping oaks healthy.

If you feel your tree or a nearby oak tree is infested with two-lined chestnut borer, contact the natural resources division or a city licensed tree care company for management options.

Emerald ash borer prevention

Emerald ash borer (EAB) is an invasive insect that kills all untreated ash trees, with the exception of mountain ash. A citywide discount is available for homeowners to treat privately owned ash trees with a preventive insecticide. The city also has a program to assist income-qualified residents with ash tree removal and treatment costs.

Visit the emerald ash borer page to learn more about EAB treatment options and assistance programs.

Elm and oak tree treatment reimbursements

The following reimbursement amounts are available for preventive treatments against Dutch elm disease, oak wilt and two-lined chestnut borer infestation:

• 50% base reimbursement
• 75% income-qualified reimbursement*

Treatments must be applied by a city-licensed tree care company to be eligible for reimbursement. View a list of licensed tree care companies on the trees page. The first treatment needs to be dated Jan. 1, 2024, or later in order to qualify.

To request reimbursement, complete the online reimbursement application. Documents required for successful reimbursement include an invoice from the contractor for work completed, proof of payment, and a completed Form W-9. Cost-share payment will be issued via check to the applicant within 60 business days of receipt of required documentation.

City cost share reimbursements will be issued once proof of payment in full to contractor has been submitted. The city will not reimburse any additional charges or fees paid for credit card processing or non-direct expenses. 

Note: The City of St. Louis Park reserves the right to adjust the cost-share reimbursement rates at any time. The rate at the time you completed the reimbursement application will be honored. 

*Income-qualified property owners are required to self-certify in the reimbursement application. Applicants must have adjusted gross income (AGI) equal to or below 80% of the area median income (AMI), adjusted for household size, as determined by the Federal Department of Housing and Urban Development. AGI can be found on your most recently filed federal income tax return.

Refer to the following chart to determine eligibility for elm and oak tree treatment reimbursements at the 75% rate.

Trees with disease, fallen trees that have disease symptoms, and trees with insect infestations such as emerald ash borer must be removed from boulevards and private property to prevent the spread of disease and pests to nearby healthy trees.

Trees required to be removed by the city will be marked with an X with orange paint by city staff.

Tree removal in the boulevard or public right of way

If a marked tree is in the boulevard or public right of way, the city will pay the entire cost of the tree and stump removal. The city will arrange removal with a licensed tree contractor.

Tree removal on private property

If a marked tree is on private property, the property owner is responsible for 100% of the removal and disposal cost. The city will arrange for a licensed tree contractor to remove the tree. Contractors selected by the city have met licensing requirements and have submitted competitive bids for tree removal and disposal. Property owners can reject the city contractor's bid and hire their own city-licensed contractor to remove a tree from private property. Visit the trees page to see a list of licensed tree contractors.

Note: Income-qualified residents can apply to have their ash tree removed at no cost through the Shade SLP Plus program.