The EAB Time Machine — Revisited

Ten years ago, I wrote an article for this newsletter about the state of emerald ash borer (EAB) and what the future of ash trees looked like then. If you have kept past newsletters, you will find the full article in the winter 2013 issue. At that time, EAB was relatively new in our area and most ash were not yet affected by this destructive insect. Fast forward to today, we have progressed upward on the mortality curve. Thankfully, death does not overrun the current story for all ash trees.

Untreated ash tree

You may be wondering about the current ash population.

Healthy, treated ash tree

Yes, untreated ash trees in SE Wisconsin have largely succumbed to the devastating effects of emerald ash borer. Outside of this area, EAB has killed tens of millions of ash trees across the U.S. Even some treated ash trees which were experiencing hidden root problems, past damage, or other structural problems have also been taken down due to these secondary issues. However, the ash trees in good health that have received preventive treatment before insect damage occurred, have continued to perform well. These treated trees remain important assets in our landscape and continue to thrive! These living ash are often ‘hiding in plain sight’ since they are fully leafed out during the summer and blend in among other healthy trees. They do not gain the same attention as untreated ash because these dead ash stand leafless and riddled with woodpecker damage.

Stump of an untreated ash tree

Going forward, the full fate of our ash trees has yet to be written. This EAB epidemic can be compared to the history of elm trees which were devastated by Dutch elm disease (DED) decades ago. There are still a set of old, remnant elm trees that have survived through DED primarily because of intervention. Recently, with the help of dedicated care and research, elms are slowly being reintroduced with new plantings of resistant elm varieties. For diversity’s sake, I remain hopeful for a similar recovery of ash in the future.

Street lined with treated ash trees

The takeaway from this update reveals that timely intervention, adhering to a knowledgeable plan, and continued treatments prove effective at sustaining ash trees in our yards. Many homeowners and municipalities continue the efforts to sustain the canopy cover offered with ash trees. We will stay on top of the current research and options to battle emerald ash borer. As this EAB story turns another chapter, we will be sure to keep you informed on the latest updates.

Related Newsletters

Consider Treating Ash Trees

There are a few ways to look at the effects of EAB: Do nothing and remove ash trees as they are killed by EAB. Proactively remove ash trees in order to lessen the landscape’s dependence on them. Plant non-ash trees to replace losses or to anticipate losses. Treat selected ash trees with the very effective, but more costly, trunk injection of insecticide for 2-years of protection (repeated every 2 years for sustained protection).

Emerald Ash Borer – What’s Your Plan?

If you are waiting for EAB to officially be confirmed in your municipality before you make a management decision, the insect is already way ahead of you.  With each new EAB find, research has consistently shown that EAB has already been in the area for 3 to 5 years.

Ash Tree Identification

Proper tree identification can be tricky. Many trees share similar attributes such as branch and bud configuration, leaf shape, and bark texture, making it easy to mistake one type of tree for another. When it comes to protecting your ash tree against EAB the first step is proper identification.