Arborist injects pesticide in ash tree on courthouse lawn



A local arborist is doing his part in prolonging the life of a mature ash tree on the Jackson County Courthouse lawn.

Forrest Willey with NaturalScape Services Inc. became a certified arborist about three years ago but has been doing the work of an arborist since 2007.

The services at NaturalScape include landscape design and maintenance as well as lawn care.

"Me and my dad were two of the first people in this county that were doing ash tree injections, and there are still just a few others that do it," Willey said.

The ash tree, which stands in front of the courthouse in Brownstown, received a pesticide injection about a week ago.

Willey said the tree once had an active infestation, so it needs to be treated every year for a while. Trees that are relatively OK can be treated once every two years.

"Around Jackson County, treatments for the emerald ash borer starts about the third week in May up until about the first week of July," he said. "As for when the treatment begins to take effect, it depends. If the tree is in really good shape, it’ll be up in the crown within days."

The emerald ash borer can cause considerable damage to an ash tree.

"It could start with a general thinning out of the crown, and when you look at the main stems, you’ll see feeding galleries where the bark is split and also little serpentine-like channels carved in the wood from the larvae," Willey said.

He said the adults don’t really do all that much damage except for munching on the leaves a little bit, so it’s the young that cause problems.

Willey said there is a bit of science involved for picking a good day for tree injections.

"You do not want a dry, hot day, especially if it’s dry, hot and windy," he said. "What’s nice is if you have a bit of humidity along with a recent rain and your soil temperature is at least 60 degrees Fahrenheit."

Willey said the tree leaves have tiny openings called stomata, and whenever they’re open, they allow a water pressure gradient to form that lets fluids and nutrients move from the roots up into the rest of the tree.

"As long as the stomata are open, the tree can pull the chemical up," he said. "So a humid or warm day is OK, but on a hot, dry and windy day, it doesn’t work very well because the stomata are pretty much closed off."

Doing an injection while it’s raining is really slow, but there must be moisture in the ground or the tree is not going to be pulling in the chemical, so it’s best to have rain a day or two before, he said.

As Willey was preparing to drill holes around the base of the courthouse ash tree, he pointed out some scattered twigs on the ground.

"These twigs are a result of cicadas laying eggs in the crown of the tree," he said. "When the female cicada deposits eggs in the stem, it causes the stem to break and fall off, so this was not caused by emerald ash borer."

To prepare for the ash tree injection, Willey first went around the base of the tree drilling holes in the sapwood, then put a plug in each opening.

He said as long as the tree is healthy enough, it would pull moisture out of the ground and pull the insecticide up through the canopy.

"I’ve got these pressurized bottles filled with insecticide containing emamectin benzoate," he said. "This tree will take about 180 milliliters of chemicals."

If an ash tree is very large and has an active infestation, it would take more pesticide.

"After this treatment, I’m going down to Salem to take care of a great big white ash, and it uses almost 600 milliliters of product," Willey said.

The process of drilling holes in the tree, attaching the tubes and administering the chemical took about a half-hour.

Willey said sometimes, the tree will close over the holes he drilled within a year.

"After the tubing is attached and the bottle is filled up with product, I have to prime all the lines and blow the air out of them, kind of like you would before you give a shot to a person," he said.

The pressurized container had a hand pump, so Willey gave it two pumps, which generated about 15 pound-force per square inch, then he bumped it up to about 40 psi.

The ash tree immediately began sucking in the green chemical through the multiple tubes attached to its trunk, almost like it was drinking through straws.

"There used to be four other ash trees on the courthouse property, but they were in pretty bad shape," Willey said. "There was one back in the corner that was considered  borderline for treatment, but the commissioners saw there was a threat of the tree dropping dead limbs on the public, so it was removed, too."

He said of the ash trees in Jackson County, unless they are being managed by a homeowner or a professional, there’s almost 100% chance they’ve got ash borer at this point.

"In some ways, emerald ash borer is worse than Dutch elm disease and chestnut blight, which we’ve had over the last century," Willey said.

After treating the ash tree in Brownstown, Willey was going to Salem to treat an ash tree on the courthouse square.

"That tree is so big that three people together probably couldn’t get their arms around it," he said. "They estimate it to be around 250 years old."

Willey said there’s a bit of community pride and a bit of personal pride in his treatment of the ash trees.

"This is one of my favorite things, working on ash trees like this one," Willey said. "I like the thought that years down the road, I can tell my my kids and grandkids I saved this tree."

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