But they're not the only farmers being affected, as CBS News correspondent Cynthia Bowers reports.
With harvest just three weeks away, the owner of the largest peach farm in South Carolina needs more hands.
Nearly a 10 percent of his 500-man workforce is still in Mexico waiting on the consulate to re-open so they can get visas. Chalmers Carr worries flu fears could threaten his state's $50 million peach industry.
"When you go to the grocery store - that just didn't appear on the shelves. Somebody had to pick that, somebody had to pack that," said Carr, of Titan Farms in Georgia.
It's not just peaches, and it's not just in Georgia. Almost every fruit and vegetable at the grocery store this summer is hand-picked by laborers like Marcello Hernandez, who would have to work nine years in Mexico to earn as much as he does in one growing season here.
The State Department says last year 64,000 Mexican workers crossed the border for seasonal jobs on farms like this one and that's just the documented workers. The potential for not getting those workers back this year could spell disaster for American farms.
Pig farmers are already feeling fallout. They lobbied to get the government to start referring to "swine flu" as H1N1. They're hoping to correct a misconception that eating pork causes the virus. Several countries, including Russia and China, have banned North American pork products.
That's an over-reaction that experts say could have a catastrophic impact on the global economy.
"There's a tremendous epidemic of fear. And that epidemic of fear causes people to shut down activities which are not really threatened by the epidemic," said Mead Over of the Center for Global Development
The short-lived SARS pandemic six years ago cost the Asian economy $18 billion. At stake this time, U.S. and Mexican trade worth $350 billion a year.
Farmers like Chalmers Carr are heavily invested in a quick resolution.
He's asking himself, "Do you walk away from a certain amount of the crop?"
That wouldn't just prove costly to growers. Fewer fruits and vegetables would mean higher prices for consumers as well.