What is Dutch Elm Disease (DED)?
Dutch Elm Disease (DED) is a vascular wilt caused by a fungal pathogen that blocks a tree’s water transport system, also known as the vascular system. This blockage causes the branches to rapidly wilt and die. The name “Dutch” comes from the early 20th-century research conducted in the Netherlands, which helped identify the cause and spread of the disease.
As the fungus multiplies inside an infected tree, the vascular tissue becomes clogged, preventing water and nutrients from reaching the branches and leaves. Without prompt intervention from a qualified arborist, the disease can spread quickly throughout the tree and to neighboring elms.Dutch Elm Disease shares characteristics with other common tree diseases in the St. Louis region, but requires a specialized treatment approach.
Symptoms of Dutch Elm Disease
The most visible signs of Dutch Elm Disease typically appear in mid to late summer and early fall. You may notice symptoms in a portion of the crown before they move throughout the rest of the tree.
What does Dutch Elm Disease look like?
- Peeling back the tree bark will show brown or purplish streaks of discoloration in the outer layer of the wood
- Yellowing/browning leaves or other discoloration
- Wilting (flagging) leaves that often turn brown, shrivel up, and may eventually fall off
- Dead leaves that have not fallen off the tree
- Wilting leaves and young shoots present at the same time
Initially, only a part of the tree crown may be affected, but symptoms may progress rapidly throughout the crown. Death may occur quickly in trees infected in early spring, while trees infected later in the summer may survive longer.’
If you suspect your elm may be an infected tree, it’s important to act quickly. Contact a certified arborist in St. Louis County for a professional inspection and diagnostic assessment.
How Dutch Elm Disease Spreads
Dutch Elm Disease is spread primarily by elm bark beetles, which act as carriers for the fungal pathogen.
- The adult female beetle creates a tunnel in the wood of dead or dying elm trees as she feeds.
- As she goes, she lays eggs that hatch into larvae that begin to feed and create more tunnels extending from the original. The pattern of tunnels is called a gallery.
- The Dutch Elm Disease fungus produces sticky spores in these galleries called conidia.
- When larvae breed in infected elms, the newly hatched adult beetles are contaminated with the conidia.
- The contaminated adults carry thousands of sticky conidia on their bodies. When they fly to healthy elms to feed on young bark, they introduce the pathogen to the new tree.
- The new tree then becomes infected with the fungus.
In addition to beetle transmission, the disease can also spread underground through root grafts, which naturally form between closely spaced elm trees and allow the fungus to move from one tree to another. Because this fungus travels so efficiently both above and below ground, swift action from a professional arborist is essential to limit damage and protect nearby trees.
Dutch Elm Disease Treatment and Prevention
Preventing Dutch Elm Disease begins with proactive care. At Omni Tree Service, our experienced ISA-certified arborists will assess the condition of your elms and create a custom treatment plan designed to stop the spread and restore tree health.
Recommended treatment options may include:
- Prompt removal of diseased trees or branches. This will limit the elm bark beetle population and eliminate the source of the DED fungus
- Using insecticides. This will kill the contaminated beetles before they can spread the disease to more elms.
- Breaking root grafts between trees. Large trees near each other are likely to have root grafts that will need to be broken to prevent the spread of the fungus.
- Injecting fungicides. This can prevent new infections or prevent the fungi from spreading to parts of a tree that are not yet colonized.
- Burning, chipping, or burying infected wood. This is done so that it cannot provide a home for beetles.
Routine inspections several times a year can significantly improve outcomes. If you’re looking for Dutch Elm Disease treatment near me, don’t wait. Early intervention is key.
Expert Dutch Elm Disease Treatment Near St. Louis County
With decades of experience treating Dutch Elm Disease and other serious tree health issues, Omni Tree Service is proud to be a trusted name in tree service across St. Louis County. Our certified arborists combine science-backed care with a personalized approach you can count on.
When your elm needs attention, we’re here to step in with thoughtful, experienced care. Call us today or schedule your consultation online.
