| MEXICALI, Mexico
MEXICALI, Mexico Like other California vegetable growers, Larry Cox oversees hundreds of Mexican farm workers picking green onions, asparagus and cauliflower in the fertile Colorado River valley.
But this farm is not in California, where illegal immigration raids are causing labor shortages and strict environmental regulations are increasing costs.
Instead, Cox's farm is just south of the border in Mexico where he can hire workers at a tenth of the cost.
Americans are farming some 50,000 acres of land in Mexico and employing 11,000 people, in spite of high crime, suspicion of outsiders and doubts back home about Mexican food safety standards.
The Bush administration's clampdown on undocumented workers and tighter border security means the flow of Mexican workers to California is drying up, Cox said.
"There has been a crackdown on illegal immigration but they haven't given us an avenue to get legal workers," said Cox, 49, driving by his irrigated fields on the outskirts of Mexicali, just a quick commute from his U.S. home.
Cox rented a small plot in Mexico in 1991 and now has 2,000 acres under lease. Other American farmers are moving into Mexico for the first time, planting lettuce as far south as Mexico's central heartland.
Two years ago, Cox had to leave around 750,000 pounds of tomatoes unpicked on his farm in Brawley, California, because he could not find enough workers at harvest time.
California's San Joaquin Valley, a rich agricultural region, usually employs around 230,000 seasonal laborers but deportation sweeps have left farmers short by almost a third, said Manuel Cunha from the area's Nisei Farmers League.
U.S. workers do not want strenuous farm jobs, said Cunha.
As well as tapping into an abundant source of cheap labor in Mexico, U.S. growers can avoid expensive environmental regulations demanded by states like California.
"We are basically being regulated out of business," said farmer Steve Scaroni, who moved 20 percent of his operations to Mexico's central state of Guanajuato in 2006.
Cox said he needed costly air quality permits to burn his asparagus fields in Brawley but in Mexico few eyebrows are raised when he sets fire to his fields to clean them.
"In Mexico they said, 'Permits? What? You just throw a match,'" he said.
Most workers on Cox's Mexicali farm earn around $10 a day instead of the $10 an hour they could earn doing the same job north of the border. But most say they prefer being near home.
"You might make a little more up there but you also suffer more," said Manuel Sanchez, 36, wrapping rubber bands around bunches of green onions.
Sanchez worked illegally in the United States for six years, but high living costs and fear of authorities made his life tough.
VEGETABLE THEFT, KIDNAPPING
Mexico, which lost huge swathes of its northern territory in a 1846-48 war with the United States, is sensitive about foreigners buying land so most American farmers just rent.
"When we first started down here we had a very difficult time. People did not want to rent ground to us," said Cox.
Vegetables and machinery have been stolen from his fields and a nearby U.S. grower was kidnapped and held for ransom, but much of the hostility against U.S. farmers has dampened.
"Now the area has come to depend on the influx of cash and I think they appreciate having these big American farms down here," said Mike Fox who manages Cox's Mexicali operation.
Farmers in the United States, some worried about unfair competition, question Mexican food safety standards. A deadly 2003 hepatitis A outbreak in Pennsylvania was traced back to green onions shipped from Mexico.
"We go over the top with food safety here because it is Mexico and there is a preconceived bias," said Scaroni who knows of a half dozen U.S. farmers who have moved to the Guanajuato region in the past five years.
(Additional reporting by Tim Gaynor in Arizona; Editing by Kieran Murray)