- 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.
- 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.