PLATTEVILLE (Colorado) - A FARM couple got a huge surprise when they opened their fields to anyone who wanted to pick up free vegetables left over after the harvest - 40,000 people showed up.

Mr and Mrs Joe and Chris Miller's fields were picked so clean on Saturday that a second day of gleaning - the ancient practice of picking up leftover food in farm fields - was cancelled on Sunday, according to The Denver Post.

'Overwhelmed is putting it mildly,' Mrs Chris Miller said.

'People obviously need food.'

She said she expected 5,000 to 10,000 people would show up Saturday to collect free potatoes, carrots and leeks. Instead, an estimated 11,000 vehicles snaked around cornfields and backed up more than 3.2km. About 12ha of the 242ha farm became a parking lot. The farm is 60km north of Denver.

'Everybody is so depressed about the economy,' said Ms Sandra Justice of Greeley, who works at a technology company.

'This was a pure party. Everybody having a a great time getting something for free.'

Justice and her mother and son picked 10 bags of vegetables.

Mrs Miller said they opened the farm to the free public harvest for the first time this year after hearing reports of food being stolen from churches. It was meant as a thank you for customers.

Farm operations manager Dave Patterson said that in previous years the Millers allowed schoolchildren and some church groups to come to the farm during the fall to harvest their own food.

He estimated some 272,000kg of produce was harvested on Saturday. -- AP