Prevent the spread of EAB across Canada: How you can save our ash trees

Tree Canada


The Emerald Ash Borer (EAB) has affected millions of ash trees in North America.  In Canada alone, EAB has now spread to five provinces, affecting ash trees in communities in Manitoba, Ontario, Quebec, New Brunswick and Nova Scotia.

While foresters have come up with novel ideas to fight this invasive pest, many of us may struggle with how we can prevent this invasion from doing further damage. But fear not, below are some simple ways you can help to save our ash trees!

Tip 1: Know what an ash looks like!

Many municipalities are encouraging residents to speak up if they see an ash tree that looks damaged or that is dying.

Before you can speak up though, knowing what an ash tree looks like might help! Ash trees native to Canada are deciduous and some common examples found in our cities include White ash, Black ash and Green ash.  Ash trees are medium to large trees with generally straight, slender trunks with large compound leaves.

Tip 2: Know the signs and symptoms

Sadly new infestations of EAB are quite difficult to detect, and usually by the time you detect the signs (i.e. physical damage to the tree) and symptoms (i.e. the tree’s response to the attack), the tree can already be heavily infested.

The common signs are:

  • S-shaped larval gallery
  • D-shaped beetle exit hole
  • Feeding notch in the leaf

And the common symptoms are:

  • Dead branches
  • Vertical bark cracks
  • Heavy seeding
  • Thinning crown
  • Premature yellowing of foliage
  • Shoots on main stem and/or major canopy branches

Early detection is therefore very important, so if you do notice any of these signs contact your local municipality right away. Because the pests spread very quickly and treatment cannot be used on an ash tree after a certain level of infestation (i.e. when the tree is dried up, has too many beetles to combat, or more than 30% of its canopy is gone), if you see something, say something!

 Tip 3: Don’t move firewood

Moving firewood from an area infested by Emerald Ash Borer to a non-infested area is a fineable offense.  This simple act is thought to be the primary way that EAB has managed to spread so quickly throughout Canada.

If you are not sure if your area falls within a boundary, we recommend staying on the side of caution – buy firewood at your destination instead and don’t move it around.

Tip 4: Join the resistance

An easy way to prevent the spread is to stay informed on what your community is doing and elect representatives taking this pest and all insects and diseases that threaten urban trees seriously.

Those communities who have the best chance of rescuing their remaining ash trees are taking a stand and setting up an EAB strategy. Check to see if your municipality has one, and if not, write and ask to set one up.


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