I was talking to another parent at my kids' school the other day who told me he had several unprotected ash trees that he was concerned about because of the Emerald Ash Borers that have invaded Wisconsin and the Milwaukee area. I was kind of surprised he didn't know anything about the medicine I've been using for several years. I also wasn't sure there was much the medicine could do for his trees is he was starting to see changes in the trees themselves. When the other guy we were talking to mentioned he just spent a couple thousand dollars getting a couple of maples cut down, it reassured me that my $150-$200 per year to save my ash trees is probably a good investment right now.
I know, in 10-15 years, I'll have paid for the tree removal in medicine, and I might still have to remove the trees, so you might be thinking I should go ahead and get the five ash trees in my yard removed. However, besides not spending the money, the trees provide shade for the yard. Besides, the kids have two swings attached between two of the trees. Yes, they also have a play set, but the trees are functional. Obviously, thousands of dollars would also be nice to have rather than spend. The lowest I'd heard from others for cutting down trees like the ones I have has been $500 a piece, which means $2500, but I'm sure plenty of places would offer to do it for $!000 a tree, or $5000. I'd have to install a wood-burning furnace to try to recoup some of the costs. And sell my car.
The trees are obviously cheaper in the short run if I can keep them alive with the insecticide, so that's what I'll do. I usually need around three of Bayer Tree and Shrub Protect and Feed. I've seen them cheaper in stores than online, so you might want to shop around. The chemical is in a concentrate, so you measure out how much you need based on tree size and then mix with water. I have five medium-sized trees (30-40 year-old trees). If you have a dozen fully-grown ash trees, it might cost you $1000 a year to treat them.
The treatment is supposed to be good for a year. I try to get it done around the first of May each year so that I remember. If you hire a service, it's probably about twice as much, but they'll send you a reminder. I'm not sure if those services use the concentrate or not. I thought there was one pro method that employed drilling holes into the trees. Whether you use a DIY system or hire out, I thought the success rate was over 90%, but you do have to keep medicating the trees until the threat is gone, which could be decades, I suppose.
So far, after several years, my ash trees are still alive and healthy. However, I did not wait until the trees were sick. In fact, I began treating our trees before the borer had been officially seen in our county. I spent a long time researching, but it kept pointing to the only solution being treating the trees each year. If you want to save your ash trees, consider using the available medicines. Make sure they claim to kill the specific bug you're after, since there are all kinds of food and insecticides that don't make any claims about Emerald Ash Borers. Be consistent with your treatment every 12 months, and you should be able to enjoy your ash trees for years to come.