▼

Ash/Oak/Elm Tree FAQs

Show All Answers

1. What is a certified arborist?

An arborist is a professional who is trained in the art and science of planting, caring for, and maintaining trees and other woody plants. The International Society of Arboriculture (ISA) provides an arborist certification once individuals have worked a minimum of three years in arboriculture or a combination of education and experience and pass an exam. A good arborist will offer a wide range of services such as pruning, removal, disease and insect diagnosis, integrated pest management, etc. There are many experienced tree services that do not employ certified arborists but will do a fine job removing a diseased or infested tree.

2. What should I ask for when I am hiring an arborist or tree company?

You should always get 2-3 written price quotes before you choose one company, ask to see proof of liability insurance and do not pay the company until the work is complete. Be wary of people that go door-to- door soliciting business, even if they did good work for your neighbor. Before hiring a company, make sure they understand what is expected with the tree removal including timeline, wood removal or chipping, and stump de-barking. You do not need to grind out the stump, if the bark is removed off the stump. For oak wilt, if you or your neighbors have healthy red oaks within 100 feet of the diseased oak(s), you should hire a company that can offer treatments to prevent the spread to nearby oaks first, before the diseased tree removal. See How to Hire a Tree Contractor for more information and additional resources.

 At this time, City of Lakeville does not require tree care companies to be licensed to work in Lakeville. Some cities require tree care companies to license with their municipality. The State of Minnesota requires all tree contractors to be on the Tree Registry List.

3. What is a Minnesota Certified Tree Inspector?

Minnesota Certified Tree Inspectors are individuals who have received training and certification to manage tree pests and diseases and are qualified to offer tree health and care recommendations. They monitor communities for new tree pests and diseases. This program was founded in 1974 as a result of Dutch Elm Disease and the emergence of oak wilt.

4. What happens when a tree is infested with emerald ash borer (EAB) , or diseased with oak wilt and/or Dutch elm disease and is marked for removal?

Public property: City Forestry staff monitor and survey the entire City for infested ash, oak and elm trees on public and private property throughout the year. We also take inspection requests from residents who notice a dying tree. Infested ash trees on City property are marked and issued to one of several work crews or a contractor, who must follow the same removal guidelines and timelines as private property owners. Sites are rechecked for compliance after the removal is complete. 

Private property: City Forestry staff will contact the property owner by mail or front door hanger to request access to the yard via a right of entry form in order to inspect and confirm the trees are infested/diseased. 

• Once infested, an ash tree showing signs of EAB such as larval galleries and/or significant woodpecker activity will be marked with an orange painted ring on the diameter of the infested tree.
• A door hanger will be left onsite and an official letter with supplemental resources will be mailed to the property owner. 
• The property owner will be required to remove the tree according to the City’s removal requirements, usually within 30 days of receiving the official notification letter. Forestry staff recheck infested trees for proper removal 30 days after the official letter was sent. 

5. Where is EAB in Lakeville?

The Minnesota Department of Agriculture has an interactive Emerald Ash Borer map it updates annually which shows areas with current EAB infestations and quarantines.

6. How can I tell if my tree has EAB?

The primary symptoms of EAB are woodpecker activity, bark splits, crown dieback and suckering shoots. If you would like additional information and pictures to help with identifying these symptoms, go to our EAB Signs and Symptoms webpage. If you see any of these symptoms and would like to confirm if your tree has EAB, contact Forestry staff at LAShadeTreePest@lakevillemn.gov.

An infested ash tree has bark splits with visible larval galleries and/or significant woodpecker activity due to the presence of EAB. City Forestry staff often use binoculars to see galleries high in the tree and can help point out the signs they used to identify the tree as EAB positive. This is one of the reasons leaf-off conditions are best for seeing EAB damage on the tree.

If we see a tree that appears early in the infestation, we will leave a door hanger alerting the property owner about the City’s Ash Injection Program in order to encourage therapeutic injection to preserve the tree and its canopy benefits.

7. What are the removal requirements for an infested ash tree?

All ash brush and wood from infested ash trees must be disposed of by chipping or by hauling to a wood waste facility following all current Minnesota Department of Agriculture (MDA) quarantines or guidelines established on a county basis. Tree removal is required within the timeline provided by the City following the property inspection and first notification of nuisance sent to the property owner. Individual extensions up to two weeks will be approved on a case-by-case basis depending on site factors such as trees requiring utility line clearance. If a tree has 30 percent dieback or less and the property owner is interested in injecting the tree, an extension to June 15 will be permitted when a homeowner-accepted bid from an MDA licensed pesticide applicator is submitted to Forestry staff prior to the removal deadline.

8. What If I don’t think I can remove my infested/diseased tree or properly dispose of the wood within the required timeline?

If you believe you will need an extension, contact the City Forester at 952-985-2724 before your deadline lapses. Extensions of up to two weeks may be granted when you provide the name of the contractor you have hired, your property address and your phone number. The site will be rechecked for completion after your extension has ended. For those worried about the cost, there may be a way to spread out the removal costs on your taxes as a special assessment.

9. How do I dispose of the wood?

• For elms and oaks, you or your contractor may grind the wood and keep the wood chips on site for landscaping. Once the wood is chipped, it is no longer a threat to spreading either Dutch elm or oak wilt disease. Grinding must occur by the deadline.
• You may have your contractor haul it off site and dispose of it for you.
• You may haul it to a wood processing facility nearby. If you are hauling ash, do not violate quarantines. Go to mda.state.mn.us or co.dakota.mn.us for more information.
• Do not sell the firewood or haul it out of the area, which can accelerate the spread of insects and disease and may be against quarantines. Go to mda.state.mn.us for more about why this is discouraged.

10. Does the stump have to be ground out and removed?

The stump does not have to be ground out, but stumps with bark intact from infested tree removal may not extend more than three inches above the ground. If the stump is taller than three inches, the stump must be completely debarked. Emerald ash borer reproduces beneath the bark of ash wood. Leaving bark intact wood or stumps on a property allows emerald ash borer to reproduce and go on to infest other nearby health ash trees. If the stump is in a high traffic or grassy (mowed) area, you may want to consider removing it for aesthetic or safety reasons, but it is not necessary for disease/insect control.

11. Should I notify the City when we finish control treatments and tree removal?

If you plan to implement control measures such as ash injections, notify Forestry staff at LAShadeTreePest@lakevillemn.gov with a copy of the accepted injection estimate from your contractor. Forestry staff will revisit each address to confirm the removal of all infested trees and wood in person when the removal deadline has lapsed, but you can contact Forestry staff at LAShadeTreePest@lakevillemn.gov if your property is ready for re-inspection.

12. Does the City of Lakeville offer replacement trees for removed ash trees?

The City of Lakeville holds an annual tree and shrub sale. Trees and shrubs offered at the City sale are offered at bulk prices. Pre-ordering begins in February of each year. Tree pickup is in April. At least two days prior to planting a tree, homeowners should contact Gopher State One Call which marks public utilities for free. They do not mark private utilities.

13. What can I do to save my other ash trees?

If you had ash trees that were not marked for removal, they are likely infested, but not yet showing signs of EAB. There are chemical trunk injections available that protect ash trees from EAB and the City offers a reduced-cost program to assist residents in preserving their shade. If a tree has 30% dieback or less, there is the possibility an ash tree can be treated and saved. Earlier is always better. Visit the City’s webpage on how to Prepare for EAB in Your Yard. If trees are not treated they will die from EAB, and if they remain standing they will be marked by Forestry staff, hopefully before they become brittle and hazardous.  

14. How do I know if my property has been re-inspected and meets the insect/disease control guidelines?

The tree inspector will  leave a door hanger thanking you for helping to protect the Lakeville community forest.

15. What constitutes a tree diseased with oak wilt or Dutch elm disease?

An oak or elm with one of these diseases show signs in June-September during leaf-on conditions. The fungal pathogen is spread by shared root systems between “like” species of trees and by a beetle. The tree reacts to the fungus and tries to limit its spread by blocking up the water-conducting tissues, The first symptom often looks like drought injury and is usually “flagging” of one or more branches in the upper part of the canopy. Flagging looks like yellow or brown curling leaves moving from the branch tips down toward the main stem. The leaves may also start curling with a dark water-stained olive-green color. As the disease progresses, leaves drop. It is easy to peel back the bark on diseased branches to reveal staining on the living tissue, adding another positive identification to the presence of the fungus.

16. Are there things I can do to protect my elms from Dutch elm disease?

The best way to control Dutch elm disease (DED) is through good sanitation, which is removing diseased and dying elms and elm wood piles by chipping or burning the wood, so bark beetles do not have a place to lay their eggs. Unfortunately, good sanitation occurs after the trees are already dead or dying.

The only preventative step to keep an elm from getting DED is to inject it with a chemical that prevents the disease from taking hold in the tree.

• If you haven’t considered preventative injections for your high-quality landscape elms, summer is the time period to do so. 
• There are some issues that you should consider if you have one or more prominent elms in your yard and are thinking about injection. The tree should be structurally sound and in good health. Does the tree shade a large portion of your yard or the east or west sides of your home, offering potential energy savings in the summer? Does the tree add significant aesthetic and real estate value to your property? Keep in mind there is a financial commitment that must be made every 2-3 years to keep up on the injections necessary to keep the tree protected. 
• A chemical is injected into the tree near the base. To do so, an extremely small drill bit is used to make holes around the root flares of the elm. In many cases, small plastic tees are inserted into the holes and then tubing is connected to each of the tees. The tubing will carry the chemical to the tees, which are inserted into the area of the tree that carries water to the upper part of the tree. When the chemical is injected correctly, the tree takes it up into the crown of the tree and it is evenly distributed to give the elm protection against DED transmitted by bark beetles.
• There are two main chemicals used to protect a tree from DED. They are thiabendazole hypophosphite (known as Arbotect) and propiconazole (known as Alamo and other generic brands). In general, the procedure should be conducted by a certified arborist or a plant health care specialist who has been trained and knows how to obtain adequate distribution of the chemical throughout the tree. Additionally, the chemicals are not sold at retail stores.
• The injections can be used therapeutically in certain cases, when the disease is caught very early, and is only effective if the disease infects 5% or less of the tree’s upper canopy. After a therapeutic injection, the diseased branch portion must be removed, plus 5-10 feet beyond the diseased portion. The chemical is not effective if the tree got the disease through shared roots from a nearby diseased elm or if it is present in a branch less than 5 feet from the trunk of the tree. When appropriate, Forestry staff will make residents aware of the possibility of injection before marking a diseased elm for removal on private property. Keep in mind that the disease progresses each day, so timely treatment is necessary to save the tree.
• Most companies offer a warranty or guarantee when they inject a healthy elm, so that if the tree gets DED within the 2- to 3-year protection time period, they will refund your money or re-inject the tree. Each company’s warranty varies so it is important to get the details before you decide on a treatment. Be sure to get quotes from at least two companies and get the warranty in writing so it is clear. Most companies have kept track of their success and failure rates and are willing to share them if you ask. There are several tree care companies who work in Lakeville who offer injection services.

17. What can I do to protect my oaks from oak wilt?

Be sure to avoid any pruning or wounding of oak branches, stems or roots from April-October of each year. Check the University of Minnesota’s website to check if it is a safe time to prune.

Visit our Oak Tree Diseases webpage for more details on managing the disease

18. What does DBH mean? What factors influence how much a tree will cost to remove?

DBH is a forestry term that means diameter (in inches) measured at breast height, which is 4.5 feet from the ground. Multi-stem trees are measured as one tree at the narrowest point above ground. Beyond size of the tree, removal pricing is based on the tree’s location within the property and the presence of obstructions such as overhead utilities, steep slopes or structures. The type of equipment that can access the tree can also influence the cost. Each company has a different business model with varying levels of staffing, education and overhead which can cause wide fluctuations in cost. Most companies carry at least $2 million aggregate in liability insurance because forestry and arboriculture work carries a high risk to the employee.

19. How did the tree inspector determine property lines, and what if I don’t think the tree is on my property?

Property lines are determined based on physical factors such as fences, mowing lines, overhead power lines (which generally mirror property lines), and aerial photos along with plat maps (when needed). If you think the tree is on your neighbor’s property, try to resolve the dispute yourselves. If you cannot agree and would like more detailed information, you can call the Engineering Department at 952-985-4500 to determine if there is a survey on file for your property.

20. What if there are power lines over my tree?

When removing any tree, it is very important that you be aware of any overhead utilities that are near or travel through the tree. The utility companies (Xcel Energy or Dakota Electric) must be notified of the situation well in advance of the tree’s removal so that they may assist you.  When you contact a utility company, make sure that you notify them that you have a diseased tree, and give them your deadline. Please notify our office if there are any delays.

There are two types of situations that occur when your tree has wires near or in it:

Pole-to-Pole: This situation involves electric service to more than one residence because the wires in your tree are connected between service poles. The utility company usually prefers to handle trees around these lines by removing as much of the tree as necessary to prevent damage to their lines and to make it “safe” for other contractors to remove. They may remove only a portion of the tree and leave the remaining wood debris. It is your responsibility to dispose of any wood left on site.

Pole-to-House: This situation involves the utility lines running from service pole to your house. It is common for the utility company to disconnect the service lines involved while you or your contractor remove the tree. They will then reconnect the service lines after the work is complete. You should set a specific time for disconnection and re-connection of your service to facilitate both the efficient removal of the tree and the restoration of your service.

Contact Information:

• Dakota Electric Association: 651-463-6287
• Xcel Energy: 800-895-4999

21. Does the City mark infested and diseased trees on its own property?

Yes—Forestry staff monitor and survey the entire City for infested and diseased ash, oak and elm trees. We also take inspection requests. Infested or diseased trees on City property are marked and issued to one of several work crews and contractors, who must follow the same removal guidelines and timelines as private property owners. Sites are rechecked for compliance after the removal is complete.