Eco Tree Company


What Is Dutch Elm Disease?

tree with dutch elm disease

In Wisconsin and throughout the United States, we’ve been fighting an uphill battle since Dutch Elm Disease (DED) was introduced in the 1930s. Dutch Elm Disease, caused by a fungus called Ophiostoma ulmi, affects American elms, Ulmus americana, which are extremely susceptible, as well as European elms. Since the 30s, we have lost hundreds of thousands of elm trees across their native range. These majestic giants of our urban canopy went from being a dominant tree along our streets, parks, and homes to being a rare specimen. The few large survivors we have deserve a high level of care to preserve and protect them.

How Dutch Elm Disease Spreads

The Dutch Elm Disease fungus is primarily spread by the native or European Elm Bark Beetle. This beetle flies from canopy to canopy, feeding on broken branches or open wounds caused by storms or improperly timed pruning on elm trees. As it feeds, the fungus is transferred into the vascular system of the tree. When this happens, the tree starts to fight off the pathogen by blocking off the water-conducting vessels to prevent further spread. Unfortunately, the elms’ self-defense mechanisms essentially overreact and end up plugging the vascular system, causing the tree to die from lack of water and nutrients.

Identifying Dutch Elm Disease Symptoms

The symptoms of Dutch Elm Disease are easily spotted during the spring and summer. Look for individual branches with leaves turning gray to brown in the canopy. If you suspect and report this to a Certified Arborist, the arborist will take a sample and look for brown streaking in the vascular system. If there’s any question as to the cause, the sample must be submitted to a tree lab for testing.

testing a tree that potentially has dutch elm disease

Pouring a solution to test for Dutch Elm Disease

Worker testing for Dutch Elm Disease

Effective Treatments For Dutch Elm Disease

enerally, if you are seeing symptoms, it is already too late to save your elm tree. This is why consistent, preventative treatment for the healthiest elm trees is very important.

Property owners who choose preventive or therapeutic treatment for an elm tree generally hire a Certified Arborist. The arborist will make several measurements and canopy calculations, then hook the tree up to an infusion system (analogous to a human I.V. at the hospital) and deliver a chemical treatment (Arbotect 20-S) to the vascular system where the chemical will be carried throughout the canopy. This treatment will protect the tree for three years from the time of treatment and is the only recommended treatment with a regular success record.

Prevention And Care For Elm Trees

Healthy elms are less likely to become infected. Regular monitoring, professional tree trimming or pruning, and avoiding root grafts with infected trees are essential preventive measures. Always prune elms during the dormant season to prevent attracting elm bark beetles that lay eggs in open wounds.

Since Dutch Elm Disease symptoms can take several weeks to months to appear, early intervention is critical. If you notice any signs of distress, such as yellowing or browning leaves, contact a Eco Tree Company immediately.

Got Tree Concerns?

Our certified arborists are ready to visit your home and assess your trees. Whether you need removal, maintenance, or suspect a disease, we’re here to help! Schedule a consultation now!