Harriston, Ont. (Rural Roots Canada) – Canadian mushroom growers are warning that new U.S. trade duties on fresh mushroom imports could drive up food prices and threaten jobs on both sides of the border.
In September 2025, the U.S. Department of Commerce launched anti-dumping and countervailing duty investigations into Canadian mushroom exports following a petition from a group of American producers, according to Mushrooms Canada executive vice-president Ryan Koeslag.
Koeslag said the Canadian industry has spent decades investing in technology and production practices, helping expand exports into the United States.
The U.S. has since imposed preliminary duties on fresh Canadian mushrooms, citing general farm tax exemptions and cash-basis accounting practices as reasons for the countervailing measures.
“They really scraped the bottom of the barrel,” Koeslag said. “We all receive general farm tax exemptions in agriculture, whether you’re growing crops, raising cattle or growing mushrooms.”
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Koeslag argued the rationale behind the duties could create concerns for the broader agriculture sector because the same tax practices are widely used across North American farming.
“It puts the entire ag industry in Canada in a risky position,” he said.
Koeslag said higher prices caused by duties could reduce demand for fresh produce.
“Every time food prices increase, particularly for fresh produce, it results in less produce being sold,” he said.
The Canadian mushroom industry employs between 6,500 and 7,000 people nationally. According to Statistics Canada, as of 2024, Ontario and British Columbia accounted for almost 93% of Canada’s total mushroom sales, although mushroom producers are found all across the country, including Highline Mushrooms, Canada’s largest mushroom producer, which has a large farm in Crossfields, Alberta and Southmill Champs, which has a large mushroom farm in Winnipeg.
Canadian mushrooms currently represent about 22% of U.S. mushroom consumption, according to Koeslag.
The industry is also highly integrated across the border. U.S. mushroom growers use Canadian peat moss, while mushroom spawn used in Canada largely comes from the United States.
“We’ve had a very long, integrated and prosperous partnership for decades,” Koeslag said.
Alongside the countervailing investigation, Canadian exporters are also facing a separate anti-dumping investigation, with additional duties expected later this summer.
Koeslag said federal and provincial governments have worked with industry lawyers during the investigation process, but the sector is still looking for stronger political support from Ottawa.
“We’d like to have a united front and identify that the reasons they’ve put forward for these duties are really unsubstantiated,” he said.
