Understanding Dutch Elm Disease

Elms are among the most beloved shade trees, prized for their elegance, stability, and long lifespans. Unfortunately, the lives of many elm trees have been cut short in recent years by Dutch elm disease. If you have elm trees on your property, and would like to improve your understanding of this menacing threat, read on. This article will help to catch you up with everything you should know about Dutch elm disease.

What Causes Dutch Elm Disease

At the heart of Dutch elm disease is a type of fungus known by the tongue twisting name of Ophiostoma ulmi. This fungus causes the tree to go into a defensive mode, thus blocking the pathways along which water and nutrients travel. In other words, in trying to block the spread of the fungus, the tree causes itself to progressively die back farther and farther.

There is another key piece of the puzzle, where the causes of Dutch elm disease are concerned. You see, the fungus that literally causes the tree to die cannot travel on its own. Instead it relies on a species of insect, known as elm bark beetles, to spread it from tree to tree. These beetles are naturally drawn to elm trees, whose bark they prefer to lay their eggs beneath. When those eggs hatch and move off to find another elm tree, they unwittingly carry the destructive fungus too.

Symptoms Of Dutch Elm Disease

The first thing you will notice should your elm tree contact Dutch elm disease are areas of yellowed leaves. These leaves may occur anywhere on the tree. They are a sign that that is the area where the elm bark beetles have set up their colony. Of course, yellow leaves can be caused by a number of different things, so it's handy to know how to verify the diagnosis.

Break off a young branch in the part of the tree with the yellow leaves. Carefully peel back the bark and then slice the branch along a diagonal plane. If the wood is mottled by streaks of brown, this is a positive indication that your tree is suffering from Dutch elm disease.

Treating Dutch Elm Disease

Dutch elm disease is very difficult to fight, unless you are lucky enough to catch it in the early stages. In that case, the first step is to treat the tree with insecticide in order to kill off the disease-carrying beetles. At this point, although the fungus can still move throughout the tree on its own, the rate at which it travels will be greatly slowed. A tree technician will then usually inject the tree with fungicides to help destroy destructive disease.

To learn more, contact a local tree service.