In Ontario, the president of independent grocer Vince's Market, Giancarlo Trimarchi, turned to Facebook to show customers that most produce on the shelves of his stores is Canadian after receiving angry emails and comments about the grocer stocking US produce.
A bitter trade war between the United States and Canada has made consumers more conscious of where their dollars go.
"Buy Canadian" movements started last year after US President Donald Trump imposed tariffs on Canadian goods.
They have intensified in recent weeks after trade talks broke down and Trump signed an executive order to change the name of Lake Ontario to Lake America.
"It is a lot more aggressive this time around than last year," Trimarchi said in an interview.
Trump told reporters in Dublin on Saturday that Canada is eager to reach a trade deal with the United States and that an agreement could come "fairly soon," while repeating his complaints that Canada has treated US farmers unfairly and should remove tariffs.
Trimarchi's four stores, spread across the Greater Toronto Area, now have about 90 per cent Canadian produce.
Trimarchi is now sourcing strawberries from Quebec instead of the United States and said he has cut his advertising budget as the changes have pressured operating costs.
"We were always put in a position where you had to balance quality versus price. Now it's quality versus price versus country of origin," Trimarchi said.
Loblaw Cos, Canada's largest food retailer, in August brought back large signs featuring a maple leaf in its produce and fresh-food sections after a brief hiatus to flag the Canadian origins of products.
Loblaw also reintroduced a "T" tag to inform customers which products are affected by tariffs and make Canadian products easier to identify.
Metro, the country's third-largest grocer, said it would continue to prioritise local Canadian products in the current context.
"There has been a permanent change in the Canadian psyche," said Gary Sands, senior vice president of public policy and advocacy for the Canadian Federation of Independent Grocers.
Canada is the world's fifth-largest importer of fresh vegetables by value.
The United States is still the biggest supplier of fresh produce, accounting for more than half of the imports, followed by Mexico.
However, the share of Canada's vegetable imports from the United States fell to 62.6 per cent in July, the latest government data showed, from 69 per cent in the same month of 2023, before Trump was elected.
More than half of Canada's fruit imports came from the United States as of July.
Trade talks broke down on August 21, spurring a new round of tariffs and counter-tariffs.
John Ambard, 27, a software engineer who lives in downtown Toronto, said he has tried to avoid buying American products when possible, preferring to support Canadian brands and businesses.
Ambard said he checks product labels and researches companies online to identify Canadian-made goods.
"I think, honestly, if I can support Canadian products and Canadian institutions through these tough times, I think that's a way to help in my small way," Ambard said.
"I'm a little bit mad with America right now with how things are going. The attitude has just not been that of a friend."
Canada's harsh winters present a challenge for fresh produce, and grocers typically rely on greenhouses, stocked root vegetables or imports, which are usually more cost-effective.
But the change in sentiment toward the United States could push grocers to explore more local suppliers, experts say, while Canada invests in building a more self-reliant food system.
The Canadian government is investing about C$3 billion ($A3 billion) over 10 years to build greenhouses to increase production during the harsh winter months.
