- What is a Minnesota Certified Tree Inspector?
In 1974, the Minnesota Certified Tree Inspector program was implemented as a response to Dutch elm disease (DED) and the emergence of oak wilt (OW). Through the Minnesota Department of Natural Resources and the University of Minnesota Department of Forest Resources, Tree Inspectors receive training and a certification in how to manage epidemic level shade tree pests. They are qualified to first identify existing tree pests/diseases, like DED, OW and emerald ash borer (EAB), in a community. They are then able to offer tree health, care and management recommendations for individual trees or larger stands based on their observations.
- What is an ISA 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. An individual with the Certified Arborist designation has had a minimum of three years of work experience or equivalent in the arboriculture field and has passed the assessment of knowledge hosted by the International Society of Arboriculture (ISA).
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.
- What should I ask for when I am hiring an arborist or tree company?
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 debarking. You do not need to grind out the stump if the bark is removed off the stump.
At this time, City of Lakeville does not require tree care companies to be licensed to work in Lakeville. All tree care contractors in Minnesota are required to be registered through the Minnesota Department of Agriculture (MDA). If you need help finding a contractor near you, try searching the MDA Tree Registry List. For more tips, visit our How to Hire a Tree Contractor webpage.
- What happens when a tree is infested with emerald ash borer, 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 and diseased oak and elm trees on public and private property throughout the year. We also take inspection requests from residents who may notice a dying tree. Infested and/or diseased 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 re-inspected for compliance after the removal is complete.
Private property: City Forestry staff will contact the property owner by mail to request access to the property via a right-of-entry form to inspect and confirm the presence of an infested/diseased tree.
If an infested/diseased tree is confirmed by a Tree Inspector on the property, the tree will be marked with a painted ring and trunk diameter size for easy identification by the property owner.
A door hanger notifying the property owner of the finding will be left onsite and an official letter with next steps and 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, which will be specified in the official notification letter. Forestry staff will reinspect the site for completion of all removal requirements once the deadline has lapsed.
- What are the removal requirements for an infested/diseased tree?
Removal is required within the timeline provided by the City.
No wood or brush debris from the infested/diseased tree can be left onsite after removal.
All stumps must be cut as low to the ground as possible or debarked if left higher than 3” above the ground. Stump grinding is NOT required.
- What does DBH mean? What factors influence how much a tree will cost to remove?
DBH is a measurement for tree size that means diameter (in inches) 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. Prices can also vary between companies due to education/experience levels of staff and type of equipment and techniques used for removal.
- How do I dispose of the wood and brush debris?
All debris can be taken to approved wood utilization sites. Infested ash wood should only be transported to sites within current Dakota County Minnesota Department of Agriculture (MDA) quarantines.
Wood may be chipped to 1” x 1” pieces and used on site as mulch.
Do not keep infested ash or diseased elm wood as firewood. Leaving bark intact on ash and elm wood allows emerald ash borer and Dutch elm disease to continue to reproduce and spread the infestation/infection further. Diseased oak wood may be kept onsite if tarped. Visit the DNR Oak Wilt Management webpage for more information.
Do not sell the firewood or take it outside of quarantine areas. Moving infested/diseased wood can accelerate the spread of insects and disease and may violate the law. To learn why this is discouraged, visit the MDA Firewood Information webpage.
- 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/diseased tree removal may not extend more than 3” above the ground. If the stump is taller than 3”, it must be completely debarked. Shade tree pests can continue to reproduce beneath the bark of a stump, allowing for the infestation/infection of other nearby healthy trees. If the stump is in a high traffic or mowed-and-maintained area, you may want to consider removing it for aesthetic or safety reasons. However, it is not necessary for insect/disease control.
- What If I don’t think I can complete the removal requirements within the provided timeline?
If you believe you need an extension, contact Forestry staff by email at LAShadeTreePest@lakevillemn.gov or call 952-985-2711 before your deadline lapses. Extensions up to two weeks may be granted when you provide the name of your hired contractor, property address and phone number. The site will be re-inspected 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. For more information, call 952-985-2724.
- Should I notify the City when work is complete? How do I tell if my property has been re-inspected?
Once the removal deadline has lapsed, Forestry staff will revisit each site to confirm the removal of all infested/diseased trees and debris. If you believe you have completed all requirements before the removal deadline, you can contact Forestry staff by email at LAShadeTreePest@lakevillemn.gov to set up a re-inspection. After all re-inspections, a door hanger will be left onsite to confirm if work is complete or if more work is required.
- Does the City of Lakeville offer replacement trees for removed infested/diseased trees?
The City hosts an Annual Arbor Day Tree and Shrub Sale, which offers a variety of trees and shrubs for purchase at discounted prices to Lakeville residents. Pre-ordering begins in February of each year and tree pickup is in April.
- How did the Tree Inspector determine property lines? What if I don’t think the tree is on my property?
Property lines are determined using GIS mapping and aerial photos, along with physical features on the property such as houses, fences and overhead power lines (which generally mirror property lines). When needed, plat maps are also referenced. If you think the tree is not on your property, try to resolve the dispute by working with neighboring properties or referencing Dakota County GIS to determine ownership. If you cannot agree and would like more detailed information, you can call Lakeville's Engineering Department at 952-985-4500 to see if there is a survey on file for your property.
- What if there are power lines over or around my tree?
When removing a tree, it is very important that you are aware of any overhead utilities that are near or travel through the tree. Utility companies (Xcel Energy or Dakota Electric) must be notified of the situation in advance of the tree’s removal so that they may assist you properly. When contacting a utility company, make sure you inform them that you have an infested/diseased tree, and give them your removal deadline. If there are any delays, notify the Forestry office at 952-985-2724.
There are two common scenarios that can occur when your tree is near power lines:
Pole-to-Pole: When lines in your tree are connected between service poles, they provide electric service to more than one residence. 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 debris left on site.
Pole-to-House: When lines in your tree are connected from the service pole to a house or structure, they provide electric service to that structure. 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 reconnection of your service to facilitate both the efficient removal of the tree and the restoration of your service.
- Dakota Electric Association: 651-463-6287
- Xcel Energy: 800-895-4999
- 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 trees. We also take inspection requests. Infested/diseased trees on City property are marked for removal or treatment and all City crews/contractors must follow the same guidelines as private property owners. Sites are re-inspected for compliance after the work is complete.
- Where is EAB in Lakeville?
The Minnesota Department of Agriculture hosts an interactive EAB map. It is updated annually and shows areas with current EAB infestations and quarantines.
- 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 a tree is in early infestation, binoculars can help find galleries and bark splits higher up in a tree. When the infestation reaches a higher level, woodpecker activity and bark splits create a “blonding” effect on larger branches and down the trunk. Winter is often considered the best time to determine the presence of EAB because woodpecker activity is easiest to see with leaves off the tree.
If you would like additional information and pictures to help you identify EAB symptoms, visit our EAB Signs and Symptoms webpage. If you see any of these symptoms on your ash trees and would like an inspection, contact Forestry staff by email at LAShadeTreePest@lakevillemn.gov.
- What can I do to save my ash trees?
The City of Lakeville has a widespread infestation of EAB. This means every ash tree within City limits is most likely infested at some level, even if is not yet showing signs of EAB. If your tree has 30% dieback or less and you are interested in saving it, a chemical trunk injection may be available. This injection can be used therapeutically after early infestation signs or as a preventative before signs of EAB are noticeable. The earlier you begin treating your ash tree, the less damage EAB will cause, increasing the long-term health and value of your tree. Chemical injections are performed in the summer and must be repeated every other year.
The City offers a reduced-cost program through a private tree care contractor to assist residents in preserving their ash trees. To find out more about our Ash Tree Injection Program and what else you can do right now for your ash trees, visit our Prepare for EAB in Your Yard webpage.
- How can I tell if my tree has OW or DED?
An oak tree with OW shows signs in June-September during leaf-on conditions. The first symptom is yellow or brown curling leaves moving from the branch tips down toward the main stem, also called “flagging.” The leaves may also start curling with a dark water-stained olive-green color. Next, the leaves drop, like fall leaf drop but occurring during the summer. The disease can kill a red oak rapidly, sometimes within two weeks. The process is usually slower in white oak species.
Symptoms of DED in elm trees often first appear in late spring and early summer but can occur any time during the growing season. Leaves on one or more branches in the outer crown of the tree will turn yellow before curling and turning brown. Look for fallen leaves strewn on the ground during spring or summer.
If you would like more information on these diseases, visit the University of Minnesota webpage on oak wilt or Dutch elm disease. If you see any of these symptoms on your oak or elm trees and would like an inspection, contact Forestry staff by email at LAShadeTreePest@lakevillemn.gov.
- What can I do to protect my oaks from oak wilt?
The best way to protect oak trees is to avoid pruning or wounding oak trees/roots between April and June, the highest risk time for new infections. Best practice is to prune oaks between November and early March, during the time that carries “no” risk for oak wilt transmission. To see if it is safe to prune oak trees, visit the University of Minnesota oak wilt webpage.
If there is an oak wilt pocket near your property, control measures can be taken to help limit the spread to your trees. Common control measures include the separation of root grafts between like-species oaks, chemical injections, and good sanitation practices. Root graft disruptions and chemical injections of healthy trees should always be done before the infected tree is removed. Keep in mind that OW does not discern property lines and often the best solution is to work with neighbors to stop the spread of the disease.
If you would like more information on OW, visit our Oak Tree Diseases webpage.
- What can I do to protect my elms from DED?
The best way to control DED if it is already confirmed in your tree is through good sanitation. Remove diseased and dying elms and elm wood piles by chipping the wood to disrupt the elm bark beetles’ lifecycle. Unfortunately, good sanitation occurs after the trees are already dead or dying.
If you have a high-quality landscape healthy elm and would like to preserve it, there is a preventative chemical injection that helps keep the disease from taking hold in the tree. Many tree care contractors offer preventative DED injections, which are performed in the summer and must be repeated every other to every third year.
Things to consider when deciding to inject your elm:
- Is the tree structurally sound and in good health?
- Does the tree shade a large portion of your yard and/or the east or west side of your home, offering potential energy savings in the summer?
- Does the tree add significant aesthetic and real estate value to your property?
If you would like more information on how to diagnose and manage DED, visit the University of Minnesota Dutch elm disease webpage.