It is estimated that there are approximately 860,000 ash trees on public and private lands in Toronto. Emerald Ash Borer (EAB) is an introduced forest pest that will kill all ash (Fraxinus spp.) trees in Toronto unless they are treated with a pesticide effective against EAB on a repeated basis.

Urban Forestry's surveys and monitoring have shown that EAB is widespread throughout Toronto although tree mortality may not be readily apparent in all areas. The City encourages private property owners to treat and retain any ash trees that are still healthy. Urban Forestry will continue, to use various means to inform the public about the EAB problem and options for treatment or removal.

Ash tree removals due to EAB on streets and in parks will occur as required to ensure public safety.

More information on EAB visit the City of Toronto website

Identifying Ash trees

Signs & symptoms of an EAB infestation:

  • thinning or yellowing of the leaves
  • long shoots growing from the trunk with very large leaves
  • vertical cracks in the trunk
  • tunnelling (S-shape) under the bark
  • D-shaped exit holes
  • branch dieback
  • tree death

Removal of Ash trees on private propertyAll requests to remove privately-owned Ash trees that are EAB infested will be exempt under the Private Tree Bylaw provisions, however you must contact 311 first to request an exemption. If your Ash tree shows signs of advanced EAB infestation, contact 311. You will be asked a series of questions. If you meet the requirements for an exemption, you will be issued a service request number and you can proceed with the removal of your EAB infested tree.


  • If the inspection reveals that false information has been provided and protected trees have been destroyed or injured, Urban Forestry may issue an order to stop any activity causing injury or destruction of trees.
  • Charges may be laid under the provisions of the City's private tree bylaw legislation. A person convicted of an offence is liable for 1) a minimum fine of $500.00 per tree and to a maximum fine of $1,000.00, 2) a special fine of $100,000.00 (A special fine is an extra fine that can be levied against the defendant upon being convicted of an offence. The Judge or Justice of the Peace has the discretion to impose the fine based on the facts of the case).

Is there anything that can be done to save a healthy Ash tree?
At the present time, a naturally-occurring compound from the neem tree marketed as TreeAzinTM has been shown to have pesticidal properties and is the only product registered for use in Canada that has been shown to be effective in the control of EAB keeping ash trees alive. The City has instituted a significant TreeAzinTM treatment program involving approximately 13,000 city-owned ash trees across the city. Pesticide treatment can occur starting in June and going until the end of August each calendar year.

If your privately-owned ash tree is still healthy enough to treat and you are considering using TreeAzin you can find more information and a list of approved applicators at the Bio Forest website.

Asian Longhorned Beetle Education and Outreach Project Sites
To further the education and outreach regarding Asian Longhorned Beetle in Toronto, Urban Forestry in partnership with Canadian Food Inspection Agency (CFIA) has established 9 awareness sites across the city. At each of these sites, one maple tree has been made to look as if it is hosting ALHB. Holes have been drilled into the trees with the edges painted black to represent exit holes and carving tools were used to mimic egg laying sites. In front of each tree a sign has been installed explaining the process, some basic information about ALHB and contact information for the CFIA if ALHB is suspected. The sites will help educate the public and act as a training ground for City staff. The sites will be maintained by UF with assistance from CFIA. The 9 sites include: High Park Milliken Park Sunnybrook Park Ourland Park Caledonia Park Ramsden Park Prairie Dr Park Ashbridges Bay Keele St and The Chimneystack Rd (York University)