South KC Perspectives

Area Ash Trees in Danger

By John Sharp

“This is going to be worse than Dutch Elm disease and American Chestnut blight combined.”

That’s the description of the devastation to area ash trees expected to be caused by the emerald ash borer that KCMO City Forester Kevin Lapointe shared with south Kansas City residents at a January 20 meeting of the Southern Communities Coalition.

Lapointe said there are about six million ash trees in the nine-county metropolitan area, representing about 7-10 percent of Kansas City’s tree canopy.

He said untreated ash trees will become infested with the borer and die, although trees treated professionally with periodic trunk injections of insecticide usually can be saved if no more than 50 per cent of their leaves and branches have died.  He added it is already too late to protect ash trees in our area by the ground application of insecticides around the trees due to the current level of infestation.

The worm-like larvae of the borer feed under the bark of trees and disrupt the flow of water and nutrients.  According to the Missouri Department of Conservation, when large numbers of larvae are present, they kill trees within one to three years.

The emerald ash borer, an Asian beetle, was first discovered in the United States in Michigan in 2002, although it is believed to have arrived up to 12 years before it was detected, probably traveling in ash wood shipping crates on cargo ships.

The borer has spread throughout much of the eastern and midwest U.S. and parts of Canada and was found in 2012 in Platte County.  Its presence has since been confirmed in Kansas City south of the Missouri River and in Leavenworth, Wyandotte and Johnson Counties in Kansas.

Since 2013 the entire state of Missouri has been under an ash borer quarantine.  According to the University of Missouri Extension, the quarantine requires specific actions to reduce the risk of borers surviving before any part of an ash tree, including logs and green lumber (as well as any firewood from all hardwood species) can be transported out of the quarantine area.  Export of ash nursery stock is prohibited.

The most effective step individuals can take to hinder the spread of the borers, according to the Conservation Department, is to avoid moving firewood (which is frequently infested) any distance.

In an interview following his presentation, Lapointe said the city is treating ash trees on public property that are properly placed and still relatively healthy, but will remove trees in bad locations and those that have already been heavily damaged by the borers.  He said small ash trees that have been planted fairly recently will be replaced by other species.

A news release by the Kansas City Parks and Recreation Department estimated there are about 20,000 ash trees on public property in the city and more than 400,000 such trees on private commercial and residential property.

Lapointe said many commercial developments and residential subdivisions such as the Fairlane subdivision in Hickman Mills have particularly large concentrations of ash trees.

Ash trees are deciduous and have branches that come off the main branch, one on each side directly opposite each other.  They have compound leaves with 5 to 11 leaflets.

The Missouri Conservation Department advises homeowners to have healthy large ash trees treated and consider treating ash trees that have less than 50 percent dead branches and missing leaves if they are valuable because of their shade or appearance.  If the trees have more than 50 percent dieback, are small or are located in poor sites, the department recommends removing the trees.

While Lapointe stressed in his presentation that treating large ash trees is considerably cheaper than removing them, he pointed out in a later interview that if nearly 50 percent of a tree’s branches have died, the tree will usually survive, but may be left with a poor shape “…since most of the regrowth is from the few remaining live branches just putting out a lot of sprout branching.”

One sign of an EAB infestation is the long, squiggly tunnels under the bark of the ash tree. Photo courtesy University of Missouri Extension

Conservation Department publications say signs of possible emerald ash borer infestation include sparse leaves and branches dying in the upper part of a tree, new sprouts on the lower tree trunk, increased woodpecker activity, D-shaped exits holes about an eighth of an inch wide, splits in the bark, winding S-shaped tunnels under the bark, tapeworm-like larvae with bell-shaped segments under the bark and the appearance from mid-May through July of half-inch long metallic green bullet-shaped beetles.

The department recommends contacting a certified arborist to discuss treatment options.  It also recommends planting a diversity of trees and shrubs as replacements for ash trees that are removed.

Lapointe pointed out that once ash trees die they become brittle and come apart very quickly.  He said that makes it dangerous for tree service workers to climb large trees during removal, sometimes necessitating the use of mechanical lifts or cranes that can add greatly to the cost.  Therefore, he said, it is important to remove the trees quickly once they die.

Lapointe emphasized in his presentation that homes associations can get much better prices for the treatment and/or removal of ash trees for their members than individual homeowners can obtain themselves and should be able to obtain free estimates for the work.  He said groups that would like him to speak may email him at kevin.lapointe@kcmo.org.   

More information on dealing with the emerald ash borer menace can be found on the Conservation Department’s website, www.mdc.mo.gov, searching for emerald ash borer treatments and reading the Emerald Ash Borer Management Guide for Missouri Homeowners published in April 2015.

Don’t know if you have ash trees?  This video may be helpful Ash Tree ID – EAB in Missouri.