For most visitors the most convenient and compelling farmers market is the Portland Farmers Market downtown in the South Park Blocks  near Portland State University and Montgomery Streets (503/241-0032, www.portlandfarmersmarket.org , 8:30 a.m.–2 p.m. Sat. Apr.–mid-Dec.).
The market attracts throngs of people, and not just for shopping: The market features famous local chefs giving cooking demonstrations, great street food carts, and musical entertainment. People-watching is of the highest caliber here, as are the breads and baked goods, locally grown fruits and vegetables, artisanal cheeses, wild mushrooms, organic meat and poultry, and nursery stock.
There’s a smaller version of this farmers market a few blocks to the north, at SW Salmon Street and Park Avenue, 10 a.m.–2 p.m. Wednesdays.