Dutch Elm Disease: What You Need to Know

Is Dutch Elm Disease in your elm trees? During late spring and early summer, symptoms of Dutch Elm Disease typically start appearing, if they haven’t already. It’s important this tree disease is addressed early, as it can kill an elm tree in as little as 1–2 years. Recognizing the symptoms may be easy, but knowing how to treat or stop the spread can be more difficult. Let’s break it down.

What is Dutch Elm Disease?
Dutch Elm Disease is a fungal infection from the Ophiostoma novo-ulmi fungi, that causes wilt and death of all species of elm trees in Minnesota. It was first found in Minnesota in 1961 and is located in every Minnesota county. While this tree disease died down for a while, it’s becoming an issue across Minnesota again.

How is Dutch Elm Disease Spread?

This tree disease is typically spread through different kinds of elm bark beetles and usually infects the outer branches first. Usually, elm bark beetles cause the spread of infection through feeding and breeding within the elm trees.

Another way this infection can spread is through a root graft. Root grafts allow water and nutrients to be passed from one tree to the other that are of the same species. When this happens, the Dutch Elm Disease fungus can move from an infected tree to one that is not infected. When possible, it’s important to have the root grafts severed before the removal of the tree so it doesn’t pass on to healthy trees. Infections that happen this way can move through the tree very quickly compared to that of an infection started through elm bark beetles.

How to Identify Dutch Elm Disease
Dutch Elm Disease can be identified mainly when the leaves on the outer crown of one or more branches starts to wilt and turn yellow, then eventually brown. Leaves tend to be strewn over the lawn in spring and summer as well. These symptoms usually appear in late spring or early summer, but ultimately can occur anytime during the growing season of the tree.

Another way to identify Dutch Elm Disease is through removing the bark of an elm tree near the wilted branches. When the bark is removed, brown streaking can be seen along the sapwood of these branches.

What to Do if Your Tree is Infected

If Dutch Elm Disease is caught early enough, it can be pruned out and your tree can then be protected with fungicides. To preserve your elm trees, it’s imperative that the infection be addressed as soon as possible. If you notice yellow wilted leaves only on one or two branches, we recommend having the infected branches removed as soon as the infection is noticed.  It’s important to remove these branches before the disease has a chance to move to the main stem of the tree branches and further into the trunk.

However, if a tree has multiple branches that are infected, the tree may need to be taken down instead and all wood that has been infected with Dutch Elm Disease should be debarked, buried, chipped, or burned. It’s then highly recommended to replace any elms trees you’ve had to remove with a Dutch Elm Disease resistant tree. While some of these resistant cultivars are not immune to the disease, they can block the spread of the fungus.

Resources on Dutch Elm Disease

If you aren’t sure whether your tree is partially or completely infected, the tree experts at Ivan’s Tree Service are trained to diagnose, treat, or even remove trees with Dutch Elm Disease. If you’re wanting to learn more about Dutch Elm Disease and resistant trees available, feel free to check out these resources;

University of Minnesota: Dutch Elm Disease

Department of Natural Resources: Tree Troubles

Minnesota Department of Agriculture

Dutch Elm Disease: Resistant Elm Trees At Ivan’s Tree Service, we take Dutch Elm Disease seriously. If you suspect your elm trees might be infected, contact us to talk to one of our tree specialists today to schedule a fee inspection and estimate to help treat or stop the spread of Dutch Elm Disease. Our certified tree specialists are here to help you ensure your trees remain healthy through a variety of tree care services in Minnesota.