As everybody should be aware of by now, the emerald ash borer has hit Greenfield and Riley Park. To date we have cut down more than 50 trees that were infested, and there are still more that will need to come down. To judge how quickly it hit, at the end of last season there were about eight trees of concern. Take a look at the park now.
I’m not going into the history of emerald ash borer in Indiana as that would take too long. However, as far as Riley Park is concerned emerald ash borer will change the face of the park for a very long time to come. Some people have wondered why we didn’t treat the trees. We did.
Riley Park has about 130 ash trees. That’s a lot of trees to treat. Due to cost we opted to do the soaking method of treatment. There are some cities that have removed every ash tree, even those not affected.
In this method you determine the diameter of the tree and pour the chemical around the base of the tree. The tree then draws this up via the roots into the tree. By doing this you hope that it will either kill the ash borers already there or prevent them from entering it in the first place.
The down side to this is that it has to be done twice a year and you hope that it rains within a couple of days of doing treatment. This method was chosen because of the lower cost of treatment, basically the hourly pay of the employee plus cost of chemical divided by the number of trees. In all it cost about $40 per tree.
Not all trees were treated; some were left untreated due to being located next to the creek. If the chemical runs off into the creek there is a danger of killing invertebrates that live there. Killing those would be bad news for the animals that eat them.
The other options were bark spraying or injections of chemicals directly into the tree. While injections are better than the other two, it is not a guarantee that the trees will survive. If the injections were given to a tree that might already be infected you only increase the life span by maybe two to three years.
The cost figured to treat by injection was close to $18,700 the first year. The cost goes up at every treatment because the tree keeps growing; therefore it takes more chemical to treat the tree. In other words, the bigger the diameter the more it costs.
For example, our largest ash tree is 40 inches in diameter, making the cost of treating this tree about $280 the first year. The 10th year it would be about $300, with no real guarantee that the bug would be stopped.
Add to that, ash trees smaller than 17 inches in diameter usually are not treated, so we would lose about 20 to 25 trees already.
This is really a problem that we should not have had to face yet. The emerald ash borer only travels about one-half mile per year on its own. By following the DNR tracking, in 2013 it was located in McCordsville, about 10 miles north; it was north of Carthage, about 10 miles east and south from here, and in Cumberland 10 miles west.
So by that it should have taken 20 years before the emerald ash borer hit Greenfield. But like I told the Boss, once you plug in the idiot factor, who knows when it will reach here. What, you may ask, is the idiot factor?
That’s the people who either don’t pay attention (gee whiz, it’s been in all the news) or don’t care or are too cheap to buy their firewood locally when they go camping and take their own. This latter is one of the reasons it has been able to spread quickly.
So what is the Greenfield Parks Department going to do? We’re going to continue to have infected trees removed and replace the trees. At this time we have about 47 trees ready to replace those cut down. Our next step is to hope that the Asian longhorn beetle doesn’t make it this area. The Asian longhorn beetle eats the other trees.