Despite the State of Oregon’s best efforts to contain the emerald ash borer (EAB) beetle, more areas of ash tree infestation are being reported. The beetle is slowly beginning to spread across the northern Willamette Valley and is heading south.
This invasive insect that kills all native and ornamental ash trees in its path was first discovered in Forest Grove (east of Portland) in July of 2022. At first, it looked as if containment strategies by the Oregon Department of Forestry might be working to reduce or eliminate the spread of the beetle. But then last summer, a whole new forest of infested native Oregon white ash trees were discovered near Scotts Mill and the Pudding River east of Woodburn between Marion and Clackamas counties some 40 miles SE of Forest Grove. State officials thought that this area of infestation might even have predated that of Forest Grove.
About the same time and more recently, the beetle has been discovered in the city of Woodburn which is located along I-5 between Portland and Salem.
The EAB has also been discovered in Yamhill County making it the fourth Oregon county the insect as reached after Washington, Clackamas and Marion counties (https://www.oregon.gov/oda/ippm/survey-treatment/Pages/emerald-ash-borer.aspx). These EAB infestations are all tens of miles apart from each other. Thus it is safe to say that the EAB has spread to numerous locations in between. What does this mean? The emerald ash borer is on the march!
Once an ash tree is attacked by the EAB, it generally takes two to three years for branches to begin dying. Little by little, the whole tree will die. One hundred percent guaranteed! Already the EAB has killed tens of millions of ash trees in the central and eastern US and up into Canada. All this is to say that the EAB has already been in our area for nearly three years meaning that more and more trees will begin dying…if not treated.
How can they be treated?
A highly effective injectable systemic pesticide is available when applied by a trained arborist who is State of Oregon licensed. The prevention rate is 99 percent and one application lasts for two years.
What can you do if you have an ash tree on your property that you don’t want to lose to the EAB?
- Learn how to identify an ash tree. Many online resources are available to help you to do this.
- If possible, call an arborist (like Good News Tree Service, Inc.) to preventatively treat your ash tree.
- Learn what the signs of an EAB infestation are and then monitor your ash tree. If your ash tree has not been treated, at the first signs of EAB, have your tree treated. Once a tree is 30 percent dead, it is too late to treat it against the EAB. It will have to be removed.
Consider this. The cost of removal and replacement of a dead tree (if it is a street tree and you live in a city where replacement is required), can be equal to the cost of treating a tree for 20 to 30 years.
For more information on the EAB and how to treat it, please watch our informational videos: https://goodnewstree.com/services-we-offer/plant-health-care/
Please contact Good News Tree Service, Inc. for more information at https://goodnewstree.com.