The Edna Valley AVA is an American Viticultural Area located in San Luis Obispo County, California south of the city of San Luis Obispo and north of the town of Arroyo Grande. It is part of the larger Central Coast AVA. The valley is roughly bounded by Lake Lopez to the south and Islay Hill to the north. The valley runs east to west, bounded to the west by the Santa Lucia Mountains. It is surrounded by volcanic mountains and characterized by black humus and clay-rich soils. With moderate sunshine, cool maritime fog, and rich oceanic and volcanic soils, the Edna Valley appellation has California’s longest growing season. The valley is kept cool by breezes from the Pacific Ocean and morning fog. The extended growing season gives complex flavors to the grapes.