Discovered in 2002, emerald ash borer (EAB) is a wood-boring beetle from Asia that over the next two decades could infest every unprotected ash tree (including the green ash tree) in North America. Jay-Lan Lawn Care defines EAB, addresses its symptoms, and discusses the available emerald ash borer treatment options.

Background & Symptoms


This infamous insect spreads extremely fast and has already killed millions of ash trees since its discovery. Specific to the United States, confirmed EAB sightings have been made across the Midwest, including Iowa and Minnesota, and as far east as New York and Maryland. The emerald ash borer lays its eggs on an ash tree’s bark, and when the eggs hatch the larvae burrow through the bark and start eating the tree’s sapwood. Consumption of sapwood unbalances water flow from the tree’s roots to its canopy, causing dehydration. Eventually, the entire tree dies.


One of the many reasons EAB is so nefarious is that outward symptoms are virtually impossible to detect. Only as the disease spreads do symptoms manifest. These include:

    • New branches growing from the lower trunk
    • Premature fall coloration
    • Dead, leafless branches at the top of the tree
    • D-shaped exit holes confirming the larvae’s path
    • Unusual frequency of woodpeckers feeding on the tree
  • A collective decline in the health of a group of ash trees


Given the high risk of EAB spreading between trees, there is tremendous urgency to administer tree disease treatment immediately upon detection. The best time to treat a tree for EAB is spring or fall, and there are several options for treatment. These include:

Bark Spray

A bark spray treatment consists of a special insecticide that is applied by a sprayer and covers the bottom five or six feet of a tree. Once the formula is absorbed into the bark, it spreads throughout the tree. The bark spray solution only needs to be applied once a year.  

Trunk Injection

Administered every 1 – 3 years, a trunk injection is facilitated via a hole that’s drilled through the bark. The hole penetrates the bark and the outer sapwood, and then an insecticide is injected. When properly administered by a licensed professional like our local lawn care company, a trunk injection can achieve a 90% success rate in the treatment of EAB. Not surprisingly, this is by far the most effective method of attacking EAB.

Soil Drench

With a soil drench, the insecticide comes in liquid or granule form and is spread atop the ground surrounding the tree, whereby it’s watered into the soil. This option looks to deliver the formula to the trees roots, which will then distribute the formula to the rest of the tree.

Tree Removal

This is the only treatment option with a 100% success rate of controlling EAB, and it only requires one attempt, but the obvious drawback is that you risk losing a tree that may be more than a hundred years old. Replacing it with a new tree is possible, since EAB leaves no lingering after-effect as long as the infected tree is properly removed and disposed of.

Call Us Before Acting

Emerald ash borer damage is serious business, and it’s important that the aforementioned options are handled by professionals. If you suspect your tree may be suffering from EAB, contact our Sioux City lawn care company today and we’ll conduct an onsite review.