KC Gardens

The Emerald Ash Borer: If you have an ash tree, think about it now

By Dennis Patton

An ash tree with classis symptoms of emerald ash borer.
An ash tree with classis symptoms of emerald ash borer. Submitted.

The so-called green menace, Emerald Ash Borer (EAB), has been in the Kansas City area since 2012. Isolated locations were found both on the Kansas and Missouri side that year. In 2013 EAB was found in northern Johnson County.

Today pretty much every county in Missouri and all Kansas metro counties except Miami have been confirmed to have EAB populations. Ash trees are exhibiting classic signs of infestation throughout Johnson County.

So what does this mean to you?

Well, that all depends on whether or not you have an ash tree on your property. But EAB will have an effect on us all.

It is still hard to believe people have not heard of an insect called EAB, which was first found in the United States in 2002 in Michigan. Since that time it has been discovered in almost 30 states. The pest targets ash species of trees including both the green and white ash found in the metro area.

The adult insect is a small metallic green beetle. It is a borer, which means its larval stage bores into the vascular system of the tree. The damage disrupts the movement of water and nutrients to support the tree. Within time the tree declines and dies.

All ash trees, healthy or declining, young or old, are at risk from this larval feeding pattern now that the insect is here. History shows EAB leaves in its path destruction of nearly every single ash tree. An ash tree will die unless it’s treated.

Why is this frightening information?

In many neighborhoods ash is the dominant tree species. It is also common in our native woodlands. Just imagine bare neighborhoods, as though the development was newly being built. Or worse, picture streets lined with mature dead trees.

EAB will change the local landscape. The benefits of these trees will be lost and people that struggle to pay the bills will face added expenses. Areas of the city may become littered with dead, standing trees.

As projected, EAB moves slowly into an area. It takes several years since first discovery for the insect population to build to levels high enough to start seeing widespread ash issues.

We are now at those levels where, if you know what you are looking for, you will find dying and declining ash trees.

The symptoms at first are not noticeable. Initially, the upper canopy of leaves starts to thin out, followed by sucker growth in the tree and branch dieback. It may take several years of infestation in a tree for a significant portion of the tree to die. But by this time it is too late to treat the tree.

If you are thinking of treating it should be done sooner rather than later, as each passing year leads to more decline.

There is good news and bad news when it comes to options in treating for EAB.

The good news is there are several treatment options that are highly effective in preventing EAB infestations. The bad news is there is no cure. Continued treatment will prolong the life of the tree. But it will not save the tree if treatments are stopped.

As you would guess chemical treatment options, while highly effective, come at a price. The decision to treat or not is really up to you. Remember, not all trees are worthy of being treated.

Before any treatment is started, determine whether the tree is in good enough condition to be worthy of the expense. As they age ash develop defects such as rot, decay, trunk injury, poor branch angles and more ailments. Many trees were also planted in poor locations. Trees with any of these issues are probably not worth the lifetime investment of treatment.

Trees in excellent condition and properly situated add long-term value to the landscape and are candidates for treatment. Professional trunk injects that will stop the EAB feeding are recommended for larger, mature trees. These treatments are usually effective for a two-year period before retreatment is necessary. It is best to start treatment before leaf thinning and branch dieback start.

Unfortunately, there is not much more to say. EAB is here and there is no stopping its spread. If you have visited Chicago, parts of Indiana or other states east of here you probably have noticed numerous dead trees either in the woodland areas or in neighborhoods throughout the cities.

his is what is coming to Kansas City in a few short years. It is sad, but each of us with ash trees has difficult decisions to make. Extension has resources for helping with EAB issues on our website at www.johnson.k-state.edu or by calling 913-715-7050.