by Ronald E. Rothhaas Jr.
ISA OH 5177A
Member, American Society of Consulting Arborists
A recent evening walk in a quiet Westwood neighborhood revealed a reality for the west side which east siders have known and lived for several years. The Emerald Ash Borer is here and trees are rapidly succumbing.
In 2011, Emerald Ash Borer was found by ISA certified arborist Kevin Griffin near Linneman and Church. That same summer, trees began dying in the parking lot of Mercy Western Hills hospital. This spring, ash tree death has intensified area wide, with rapid expansion on the west side. While Anderson Township, West Chester, and Blue Ash are well on their way to losing all untreated ash trees, the wave is now sweeping across western hills.
Most ash trees I saw along Coral Park Drive in Westwood now have the borer. Two trees went from 100% alive to near death in a few months on Pershing Court. An 80 foot ash stands dead near Ramona, and another large ash near that intersection is 1/3 dead and likely in its last year of viability.
The purpose of this article is not to spread undo alarm, but rather to bring to light a stark reality. If you have been waiting to treat your ash tree, your time is up. This time next year, many west side ash trees will be too far gone to treat. Ashes are showing signs of infestation in many areas, including but not limited to Anderson Ferry, Boudinot, Coral Park, Ferguson, West Tower, Veazey, Urwiller, Cheviot, Airycrest, Goda, Bridgetown, Addyston, White Oak, and Mt. Airy Forest.
We now have considerable experience with this insect. We know that it starts slowly then expands rapidly like a wildfire out of control. The slow initial spread westward likely lured many into a false sense of security, but no more. The borer is here. Many trees are obviously infested to the trained eye, even if laymen cannot tell. Diagnosis of an individual tree is academic. ALL ash trees will die. It may take one year or it may take several, but they will die.
The good news is that treatment is 98% effective IF done properly. Unfortunately, many believe that garden center solutions will stop the pest in all ash trees. One radio personality likes to tell people that these treatments are the way to go. My own experience is showing that even doubled rates with professional grades of these materials still allow for some degree of infestation, although studies show that the professional rates are adequate for keeping trees alive. I have personally looked at a 1/3 dead ash in a high infestation area which was treated with the low dose over the counter rate. The dosage was the only problem I could identify.
The advice put forth by universities and repeated by professionals such as myself and radio gardening expert Ron Wilson of Natorps is much more sound. While garden center solutions work in smaller trees, studies show decreased effectiveness on large trees. Professionally injected Emmamectin benzoate is working on larger trees and providing 98% control. This material, trade named Tree-age, must be applied every other year until the wave of high insect activity has passed. While the jury is still out, it now appears Tree-age insecticide levels may remain high enough to protect trees in the post-die off time frame to provide 3-4 years of protection, perhaps 5-10 years down the road. Soil injected Imidicloprid at the double rate protects trees in studies but MUST be applied annually at the high rate and still seems to allow for a degree of damage, according to trees I have looked at.
If you have ash trees, you will be dealing with Emerald Ash Borer very soon if not already. You will either treat your tree(s), cut them down, or they will die and ultimately fall down, a threat to lives and property. There have thus far been no instances of ash trees surviving the infestation wave. True, some survive longer than others, but 100% death of untreated native ash appears inevitable.
A city forester told me she is writing orders on the east side to homeowners with dead ash trees. They are a danger to the community and local governments can and often will enforce removal if the tree threatens the right of way or adjoining properties. Yes, for some this is an economic disaster, but it is here and it is now. The time is past to ignore the Emerald Ash Borer.
More unbiased research based information can be found at http://www.emeraldashborer.info/. Arbor Doctor LLC treats for Emerald Ash Borer and also maintains an extensive website with an Emerald Ash Borer section and Emerald Ash Borer blog. This can be found at http://arbordoctor.com/. Updates are also posted on our Facebook page.