Over the past few weeks many people in Cincinnati have asked when the best time is to treat their ash trees for the Emerald Ash Borer.  Several mentioned that they had heard that April was best, and some said a friend told them that is was too late in the season to treat ash trees for Emerald Ash Borer.

In order to answer this question we need to be aware of two variables; the life cycle of the Emerald Ash Borer, and the type of treatment used.

The adult beetle emerges starting early May, leaving its distinctive “D” shaped exit hole 1/8th inch in diameter.  Adult beetles continue to emerge through June. Eggs are laid starting mid May and continue through  to August.  These eggs take seven to ten days to hatch.  The larvae then tunnels under the bark and starts feeding.  This is the highly destructive phase of the cycle and lasts through October.  The larvae pupates over winter and in early spring the adults start to emerge.

There are several treatment types.  Two of the most common are soil drenching and injection.

Soil drenching: A channel is dug around the tree and filled with imidacloprid formulation.  This takes four to eight weeks to be absorbed into the root system and take effect.  That’s why some say April treatment is best, because the soil drenched tree will be ready for the emergence of the adults in May, and continue to kill the larvae through the fall. Because of the delay in soil drenching taking effect, treating later in the year is less effective. Also, this method need to be repeated every year.

Read about the unintended consequences of soil drenching.

Injection:  The solution that Back Tree Service uses is tree injection with TREE-age.  This has the advantages of taking effect within only 72 hours and remains effective for two years.   Therefore injecting late in the cycle is just as effective as in the beginning of the cycle.

Therefore, the answer to the question on the best time to treat for Emerald Ash Borer is Spring though Fall with TREE-age when the leaves are on the trees.  Let’s face it, if the trees are getting consumed right now, why put off treating it until next year?  Once the ash borer infests an ash tree, it takes only two to three years to kill that tree.  So the earlier they are treated, the less damage to the tree.


When treating ash trees in the Cincinnati and Dayton area, a question that we are commonly asked is “What is your process to protect ash trees from the Emerald Ash Borer?”

This is a good question and has many people curious to learn the answer.


As you may already be aware, we inject the ash tree with a special solution of Emamectin Benzoate, called TREE-äge.  But how exactly is that done?

Well, we use small plugs that are placed in the trunk around the tree, and approximately six inches apart.  To do this, we drill the holes into the trunk two inches deep and close to the base, maybe a foot or two from the ground.  The plugs are then tapped into the holes, and set.  These plugs are then injected with the TREE- äge formulation.

Arbor Plugs

Plug Placement








In order to determine how many plugs to install, and how much TREE-äge to inject, the first step is to measure the diameter of the tree at 4.5 feet above the ground.  This is called Diameter at Breast Height, or DBH.  Some people are fascinated that we use a special tape measure that has the linear measurement already divided by Pi to give the diameter.

Once we have the DBH, a chart is consulted that shows how many plugs, called sites, are to be put in the tree, and how much TREE-äge per site.  As one might expect, the larger the tree’s diameter, the more sites (plugs) it needs and the more TREE-äge it needs per site.

For example, a six inch ash tree would have three sites at six milliliters of TREE-äge each, an 18 inch ash tree nine sites at nine milliliters, and a 32 inch diameter ash tree would take 17 sites at 15 milliliters per site.

The key is to get the right amount of TREE-äge into the tree.  And, under ideal conditions, the formulation will be up in the twigs in 72 hours.

The Emerald Ash Borer larvae feed on the inner bark of the ash tree.  Any larvae are exterminated by the TREE-äge formulation on contact.

This ash tree treatment has been proven effective for two years, and so we contact our clients every two years in order to renew the protection of their trees.

The following guide was put together by the Ontario Ministry of Natural Resources in Canada.

As the title indicates, it provides a simple, straightforward explanation of how to detect ash trees with the Emerald Ash Borer.

As you drive around the Greater Cincinnati area, you can see ash trees in that clearly show signs of stress, especially in places like Anderson Township and Morrow.  This guide will be of assistance in detecting if your tree might be infected with EAB.

A Visual Guide to Detecting Emerald Ash Borer Damage

As you may already know, Back Tree Service has successfully treated over 5,000 trees saving them from the Emerald Ash Borer.

One of the questions the our technicians are frequently asked by clients is how long will it take to inject their ash trees.  This depends on what some technicians refer to as “The Mood of the Tree.”

In the Greater Cincinnati, Dayton and Northern Kentucky areas, the most common ash trees that we inject are White Ash and Green Ash.  Typically the White Ash takes the TREE-age formulation injection faster than the Green Ash due to its physiology.

One of the most profound revelations on how fast a tree will accept the formulation came at YMCA Camp Kern.  You may know Camp Kern as the location of the Ozone Zipline.

A couple of months ago, we went to Camp Kern to treat ash trees that were used to support some of the Ozone Zipline platforms.  These were very tall trees, perhaps 90 plus feet high and over two feet in diameter.

We injected the first ash tree without much delay.  But after starting to inject the second ash tree, it just shut down.  In other words, it just stopped accepting the TREE-age formulation.  And within a minute or two the rain started.  It was as if the ash tree knew that it was going to rain and stopped in anticipation.  This was truly remarkable as we tend to think of trees as fixtures, and not sensitive living things that sense and respond to changes around them.

Another influence in how fast ash trees take up the formulation is the amount of moisture in the soil.  Too much and the tree will not be “thirsty”.  If the ground has been dry for a while the tree will also be slow to accept the formulation.

If the tree trunk has damage, or flat spots that indicate that part of the tree slowed in growth, or the roots have been damaged, the tree will most likely take longer to inject.

Large trees take more formulation, and are also slower in accepting it.  This is especially true later in the day when the temperature is high.

Other factors include humidity, clear sky vs. cloudy, and soil condition.

In conclusion, a healthy tree is more likely to take the formulation faster than a tree that is stressed, but the time to inject depends on the “mood of the tree.”

This article from the Kentucky Department of Agriculture gives a clear strategy to combat the spread of the Emerald Ash Borer.

This is useful advice to everyone, whether in Northern Kentucky, Cincinnati, Dayton, or anywhere in Ohio, Kentucky and Indiana.

‘Buy Local, Burn Local’ firewood to help stop spread of emerald ash borer

Monday, May 23, 2011
For more information contact:
Bill Clary
(502) 564-1137

FRANKFORT, Ky. — Agriculture Commissioner Richie Farmer reminds all Kentuckians that they can do their part to control the emerald ash borer by always buying local firewood.

The emerald ash borer (EAB) was first discovered in Kentucky two years ago on May 22. The week of May 22-28 is recognized as Emerald Ash Borer Awareness Week nationwide.

“A good rule of thumb for firewood is ‘buy local, burn local,’” Commissioner Farmer said. “That’s an easy thing Kentuckians can remember to help stop the spread of the emerald ash borer while helping our state’s hardwood producers.”

The movement of infested firewood contributes to the borer’s spread. Quarantines have been established in Kentucky and other states with confirmed infestations because EAB larvae can survive hidden in the bark of firewood.

Commissioner Farmer and other officials urge Kentuckians to take the following steps:

  • Don’t move firewood, even within Kentucky. Don’t bring firewood with you from home to campgrounds or parks. Buy all your wood there, and don’t take extra wood back home.
  • Don’t buy firewood from outside Kentucky. If someone comes to your door selling firewood, ask them where the wood came from. If it came from outside Kentucky, don’t buy it.

The EAB (Agrilus planipennis) likely arrived in the U.S. in 2002 in southwest Michigan hidden in wood packing materials commonly used to ship goods. On May 22, 2009, officials with the Office of the State Entomologist announced the first confirmed findings of the EAB in Kentucky.

State officials since have quarantined 22 Kentucky counties, prohibiting the movement of firewood, ash nursery stock, green ash lumber, and other ash materials. The quarantined counties are: Boone, Bourbon, Boyd, Campbell, Carroll, Fayette, Franklin, Gallatin, Grant, Greenup, Harrison, Henry, Jefferson, Jessamine, Kenton, Oldham, Owen, Pendleton, Scott, Shelby, Trimble and Woodford. The EAB has been found in Boone, Boyd, Campbell, Fayette, Franklin, Greenup, Henry, Jefferson, Jessamine, Kenton, Oldham, Owen and Shelby counties.

For more information about the EAB, visit http://pest.ca.uky.edu/EXT/EAB/welcome.html.

This recent article in the Bowling Green Daily News explains what Kentucky is doing about the Emerald Ash Borer problem.

The Great Outdoors: Bad news bugs

By GEORDON T. HOWELL, For the Daily News
Saturday, May 28, 2011 11:32 PM CDT

If you’ve noticed purple boxes tethered to the limbs of trees alongside county roads the past couple of years and wondered what purpose they served, you are not alone. More than 5,000 of these purple prism traps have been placed throughout Kentucky, with a large concentration in WarrenCounty, to track a foreign invader that has taken up unwelcome residence in the Bluegrass. The purpose of these traps is to monitor the spread of the emerald ash borer. The small insect, native to Asia, preys on and subsequently kills our ash trees as its larvae consume the trees’ inner bark and upsets the flow of water and nutrients. Usually, affected trees die within two years because of the borer larvae’s disruption of the trees’ life processes.

Amazingly, this bug wasn’t even discovered in the United States until 2002, when ash trees in the Great Lakes region began to die off. Since then, the green bug and its destructive young have colonized trees throughout a large area, which includes trees in northern Kentucky as of 2009.

Yet, how can a tiny insect that cannot fly much more than a half-mile from where it emerges spread so quickly in such a relatively short amount of time? The answer lies in us, the human factor. Just as the ash borer most likely arrived in wooden shipping containers carrying goods from far away, American campers now unknowingly spread the insect by packing firewood from home and then traveling hundreds of miles to camping spots, which subsequently become the new habitat for the emerald ash borer. For this and other similar reasons, Kentucky State Parks does not allow outside firewood to be brought in so that exotic pests are not introduced to our forested lands.

The repercussions of the borer’s expansion could be quite bad, considering that the Kentucky Division of Forestry estimates there are more than 220 million stems of white and green ash growing within the state. That equates to a whole lot of susceptible trees on the hillsides and in folks’ yards that could fall victim to this foreign invader.

Twenty counties in Kentucky are under a quarantine to prevent the borers from spreading, which means that permits must be had to move certain articles, such as unprocessed logs, firewood and ash nursery stock, which may harbor the adults or larvae of emerald ash borers.

In our immediate area, where no emerald ash borers have been located, it is suggested only to monitor the ash trees on your property regularly and withhold any treatment of insecticide.

Ashes are easily recognized with a bit of practice, either by searching for a photo online or utilizing a field guide to distinguish them from other similar looking trees like elms. More information about the emerald ash borer, such as how to identify them and more about the insects’ life cycle, can be gathered online at www.emeraldashborer.info. Probably the single greatest take-away from this invading insect’s impact on the country thus far is that we all need to constantly be aware of what each of us takes away from or brings into our local outdoors and the implications that even an armful of firewood for the campsite may have in our surroundings.

— Geordon T. Howell is outdoors columnist for the Daily News. He may be reached by e-mailing highbrasshowell@yahoo.com.

This article, from the Cincinnati Enquirer on June 20, 2011,, shows Back Tree Service’s own Darrell Perkins injecting an ash tree with TREE-age.


Emerald ash borer cuts swath of destruction

‘These beetles are unstoppable … It’s moving quickly and it’s everywhere’

Some are comparing it to a forest fire.

The spread of the emerald ash borer, responsible for the death of millions of ash trees in the Midwest, is moving about 40 times faster than it was several years ago, local experts said.

Joe Boggs hasn’t seen the view of Greater Cincinnati from an airplane, but he’s sure there’d be a noticeable trail of destruction.

“You drive up and down Interstate 75 and people can see dead trees to the east and west,” said Boggs, assistant professor with Ohio State University Extension and the OSU Department of Entomology based in Hamilton County.

“Our infestations are moving pretty fast.”

Since the first beetles were found locally in Warren County in 2006, they have now infiltrated all seven local counties in Greater Cincinnati and Northern Kentucky: Butler, Clermont, Hamilton and Warren in Ohio, and Boone, Campbell and Kenton in Kentucky.

Five years ago, the spread of the ash borers moved about a quarter- to a half-mile a year, Boggs said.

Today, he estimates they are moving about 20 miles per year.

Some of the worst areas include Anderson Township and Monroe, two communities that marked the first sightings for Hamilton and Butler counties.

Local governments are trying everything possible to control the invasive beetles, which were first discovered in Detroit in 2002. The most common treatments these days are soil or trunk injections, using insecticides to kill the ash borers. The most recent idea came earlier this month when officials in Wisconsin released a Chinese wasp they think may kill the China-native beetles. Ohio State University researchers have contacted local officials, scoping out suitable places in Greater Cincinnati to test the bug-eat-bug method.

Boggs isn’t sure when the wasps, which he calls “bio-allies,” may be released in Greater Cincinnati. If the method proves to be effective, it probably won’t wipe out the beetles, he said. Still, it might reduce the population to a more manageable level.

There are three species of wasp that were found in China that naturally prey on the emerald ash borers. Boggs said two of them use stingers to lay eggs inside ash borer larvae that feed on and kill them. The third does the same, but targets ash borers’ eggs.

“Researchers are still trying to learn how this works. Number one, the wasps are hard to raise, so it takes time to figure out if we can raise enough to release them,” Boggs said. “The second is, once they’re released, how long does it take?”

Meanwhile, Cincinnati is one of 12 communities in the country receiving free soil injections through the Legacy Tree Project. A chemical company called Valent provides the treatment at no cost for five years.

A total of 110 ash trees in Mount Echo, Mount Airy and Ault Park were enrolled last year. Other communities to use the program include Wyoming in Hamilton County, Indianapolis and another small community in Indiana, one in Wisconsin and seven in the Chicago area.

David Gamstetter, natural-resource manager for the Cincinnati Park Board, says the city’s 5,000 native ash trees make up about 10 percent of the trees in city parks and of those, about 1,000 have been removed.

Although the tree injections are not a long-term solution, it buys time for his department to find a better solution.

“These beetles are unstoppable,” Gamstetter said. “It’s moving quickly and it’s everywhere.”

In 2009, Springdale was the first local municipality to use a trunk injection, shelling out nearly $10,000 to treat 250 trees. The need for treatment has become so high, the company that served Springdale, Back Tree & Landscape, set record profits from fertilizing and injecting ash trees.

When the beetles move in, trees typically die within five years of infestation. These days, Boggs has seen some green, healthy trees become brittle shells in as little as a year.

“When there’s a forest fire, it starts in one place and kind of sits there burning,” Boggs said. “But as it gets larger, it starts moving faster. That’s kind of where we’re at.”

Officials are reminding residents to inspect their ash trees and look for infestation. If found early enough, many trees can be saved.

Some remain optimistic because trends suggest that once the ash borers have caused enough damage in a region, they may move out in search of better pastures.

Some researchers, looking at tree rings from Detroit, believe they may have arrived about 20 years before they were noticed in 2002.

Meanwhile, officials in Ohio announced last week that another tree-killing bug had been discovered in Clermont County. The Asian long-horned beetle can kill several types of trees, including the state’s signature buckeye tree, and sparked a quarantine expected to soon include all of Tate Township and East Fork State Park. (That means it would be illegal to take any hardwood out of those areas.)

“The one thing the emerald ash borer has taught us is to be constantly vigilant for non-native pests,” Boggs said. “I wish more than anything else in my career that someone would’ve figured this out years and years ago.”

For more information on emerald ash borers, contact the Ohio Department of Agriculture or visit www.agri.ohio.gov