Invasive fungus that kills oak trees was near the border in 2021 now it's spreading across Ontario

In December 2021, an invasive fungus infamousfor decimating oak trees was half a kilometre away from the Canadian border.

Last month, oak wilt crossed the border and was spotted in Niagara Falls.

It was Canada's first-and-only sighting at the time but not any more.

The tree disease has been spotted in Springwater, Ont., north of Toronto and has been reported at least three times in Niagara-on-the-Lake, Ont., according to the federal government.

"To help prevent the spread of these detections, movement restrictions are in place on affected properties. We are working with other federal, provincial and municipal governments to survey the areas and determine next steps," reads a federal government webpage.

Meanwhile the Canadian Food Inspection Agency is telling people in Niagara-on-the-Lake to check oak trees for any signs of the disease.

What is oak wilt?

The federal government webpagesays a fungus calledBretziella fagacearumcauses oak wilt.

It says red oak trees are especially vulnerable and can be killed in a single season.

"Oak wilt is spread naturally through root grafts or beetles carrying fungal spores. Oak wilt does not affect human or animal health," reads the webpage.

Richard Wilson, a retired forest program pathologist with the Ontario Ministry of Natural Resources, previously told CBC Hamilton oak wilt is similar to Dutch elm disease, beech bark disease, and white pine blister rust all of which have done "widespread damage."

Lauren Bell, program manager of theInvasive Species Centre in Sault Ste. Marie, Ont., previously saidsome signs of oak wilt include:

• A white, grey or black fungal mat beneath the mat.
• Cracking along the bark of the oak tree, which is an indicator of the mat.
• A sweet, fruity smell, akin toJuicy Fruit gum.
• Falling leaves or wilting and bronzing edges of leaves, starting at the top of the tree.

How other cities are preparing

Cities near Niagara, like Hamilton, are bracing for the impact of oak wilt.

Lauren Vastano, a city spokesperson, said Hamilton's strategy is being developed based on a federal response framework.

"This management strategy will also be informed by the lessons learned by city staff in executing the emerald ash borer response plan," Vastano said.

"Forestry staff and arborists have received oak wilt identification training and many environmental services staff are also receiving oakwilt identification training from the project manager of forest health.

What to do to stop oak wilt and how to report it

The federal government says people shouldn't prune oak trees between April and November.

They also shouldn't move firewood.

If someone spots oak wilt, they should contactthe Canadian Food Inspection Agency online.