Clint Brown began planting vegetables at age 4. His then babysitter, a retired gentlemen with an interest in gardening, got him started. Now 17, Clint has his own gardening business -- a venture that began four years ago with a bumper green bean crop and success at the Le Mars farmer's market. "He sold them so fast,"said Audrey Brown, Clint's mom. "I think that's what got him hooked." Clint's gardens are on his parent's Audrey and Steve Brown's farm west of Merrill. In April 2006 Clint got serious about his gardening business by building his first high tunnel structure, which...