The emerald ash borer is an invasive tree pest that kills more than 99% of ash trees that it is present in. Learn about our response below.

On this page:

  1. About emerald ash borer
  2. Our response
  3. Injection program
  4. How the program affects your neighbourhood

About emerald ash borer

The emerald ash borer (EAB) is a destructive tree pest that kills ash trees. The winged adult lays eggs on ash trees, beneath the bark. Larvae hatch and feed beneath the bark, disrupting the tree's circulation of water and nutrients, causing the tree to die.

The presence of EAB is fatal to ash trees. Once infested, trees typically succumb to emerald ash borers within two to three years but can die within months of EAB first being detected. For more information, please visit Natural Resources Canada.

Our response

We responded in two ways:

  1. To extend the life of some ash trees, TreeAzin chemical treatments were injected and reapplied every 1 – 2 years. This delays the impacts of EAB on ash trees, keeping these trees for as long as possible to contribute to our urban forest canopy. These trees will eventually fail to EAB and need to be removed.
  2. We removed ash trees affected by EAB to reduce the risk posed by dead trees near property. To date, approximately 5,000 trees have been removed. Our goal is to replace most street trees lost to EAB by 2022.

Injection program

When EAB was first identified in Kitchener, we injected approximately 1,400 trees with the chemical TreeAzin. This reduces the impact of EAB on ash trees by making them less appealing to EAB and by reducing the impacts of the larvae. However, it does not fully protect a tree. TreeAzin treatments may extend an ash trees life when in an area impacted by EAB, but does not prevent the eventual decline of the tree.

By 2017, only 1,000 trees remained in the program, and by the end of 2021 less than 300 trees will remain under treatment. Ash trees that will be removed can be found on our online urban forest story map by selecting the “Trees in Your Neighbourhood” tab and zooming into the map. Ash trees to be removed are shown with a black “X” symbol.

How the program affects your neighbourhood

We mark trees that will be removed with two vertical pink dots. You may see these dots on a tree that we have injected with TreeAzin in the past if it has emerald ash borers.

If we mark a tree for removal, it is because it is unstable and can pose safety risks. We will not continue injecting the tree. Please do not inject trees at your own cost.

If you have an ash tree on your property, we recommend consulting with tree care companies about its care. Before starting work, we suggest getting at least three estimates.