BROOKINGS — If you have an ash tree in your yard or along the boulevard, you can expect to hear from the city in the days, weeks and months ahead.

You can blame the emerald ash borer for that. The beetle is an invasive, wood-boring insect that has an enormous appetite for ash trees — one that ultimately kills those trees. And guess what? If you haven’t heard it already, well, here’s the news: That beetle has been found in Brookings.

“We are now under a quarantine — which means that hardwoods are not to leave outside of Brookings County,” Brookings Parks, Recreation and Forestry Director Kristin Zimmerman told the Park & Recreation Board on Monday night. “It is also recommended that ash trees are not removed between Memorial Day and Labor Day. That’s when the bugs are alive and moving around in the trees, and if you cut it down the bugs will leave the tree and go to the next one.”

The beetle was first found in South Dakota in 2018 and, in the intervening years, has made further inroads in the state — now including Brookings County.

Brookings hasn’t been sitting idly by during those years. It’s been using that time to reduce the number of ash trees in the city, including in Hillcrest and Pioneer parks. But even with those advance preparations, it’s still going to be something of a shock to residents, Zimmerman said, when crews further step up their game now that the emerald ash borer has officially taken up residence in the city.

“There’s been some proactive approaches, but now that we have confirmed cases it’s going to be a lot more aggressive,” she pointed out. “A lot of what we’re doing is educating the public about what emerald ash borer will do to our tree canopy and our urban forestry program. It’s going to be significant.”

That public education is multifaceted, and will include door hangers at the time a tree is marked and postcards sent to property owners detailing the process. Zimmerman added that a series of meetings with community groups are planned, along with the topic being discussed at study session of the City Council on Aug. 27.

“That’s a discussion we’ll have with each homeowner,” Zimmerman said. “Residents will have the option, if they want to keep that tree in the boulevard, to pay for that tree — but we cannot treat every ash tree, as much as we want to be able to treat every ash tree in Brookings, we cannot.”

During Monday’s meeting, Zimmerman showed board members and the audience a slide of the mortality rate of ash trees once emerald ash borer arrives covering a span of 16 years. To say the chart’s projections looked grim would be an understatement.

She said forestry experts from South Dakota State University believe that Brookings is 2.5 years into its infestation, based on the size of the larvae found in ash trees in the city. According to the chart, about five years from now, 10% of the city’s ash tree canopy will be dead and that, 10 years from now, 85% of the city’s ash tree canopy will be no more. And by year 15? No more ash trees. Really. Gone. All gone.

“To put that in perspective, about 23% of our boulevard trees — so that’s basically between the sidewalk and the street — are ash trees. So it’ll be noticeable,” Zimmerman said.

Beyond the boulevards, there’s also the shelterbelts to consider. That’s where people will see some of the biggest impacts, because they’re — and this includes the shelterbelt at Edgebrook Golf Course — are comprised of 80% to 90% ash trees. Right now, the city is preparing to take down poorer-quality ash trees in those shelterbelts, but those operations won’t commence until after Labor Day, Zimmerman said.

So, to be blunt, it’s a not-so-positive future for ash trees in Brookings. There is some hope, however, via injections that offer protection from the predations of the emerald ash borer.

With this in mind, Zimmerman pointed out that some of the more sturdier ash trees will receive treatment — indeed, some already have — while less-desirable ash trees will be axed.

“We’ll be staggering them, so we’ll take two out of every three trees, if you think about it that way,” she said of the street tree removal effort. “Just because you don’t want to go down a street — I don’t want to go down a street — and it be completely clear-cut of all trees.”

While the injections are something of a panacea for worthy ash trees, there are two caveats: They have to be applied every two years, and, per earlier reporting in the Register, can cost around $200 or so per year.

If that sounds like it’ll involve a bit of work and attention, well, that’s because it does. It’ll keep the ash tree alive, though, and that’s a much better thing — especially since that if the tree dies, it’s going to hurt your bank account a whole lot more.

“It’s really important that homeowners are really proactive on removing their ash trees because we want to avoid standing dead trees,” Zimmerman noted.

She said the cost for tree removal on private property could spike a couple thousand dollars if the tree is already dead. This is due to a number of factors, such as if there’s fencing in the way, if it has to be climbed and taken down in sections, equipment usage and so on.

“It’s really important that the public stays really on top of your ash trees,” Zimmerman said.

She continued, “If you don’t know what kind of tree you have in your yard, I would encourage you to use the Engage Brookings app. You can take a picture of your tree and just upload it, and we’ll comment back with whatever kind of tree it is.”

So, the battle against the emerald ash borer beetle has finally arrived in Brookings. How that battle ends — and what the city’s canopy will look like afterward — depends a lot on how its residents handle the new nemesis.

“It’s kind of all hands on deck — we’re all communicating and making sure that we’re being proactive as much as we can,” Zimmerman said.

— Contact Mondell Keck at mkeck@brookingsregister.com.