The Pacific Northwest Coast & Valleys region includes the Coast Range, Puget Sound Lowlands, and Willamette Valley.
Oregon Coast has a cool, long season of 190 to 250 days. Gardening isn't easy because of the wind, fog and cool temperatures. However, if you match your plant needs and garden design to the coastal climate, gardening by the beach can be rewarding.
The Coast Range has warm, relatively dry summers and mild, but very wet winters. Cranberries are grown commercially and high humidity is great for mushroom cultivation.
The Puget Lowlands include the areas around the Puget Sound in Washington. It is in a glacial trough with many islands, broad rolling lowlands, some plains and low mountains. The climate is mild and because it is affected by the rainshadow of the Olympic Mountains, the rainfall is less than other nearby areas. Farms in this region tend to be small and family-operated. Major agricultural crops are red raspberries, flower bulbs, and seeds (spinach, beets, and Brussels sprouts). Larger cities include Seattle, Tacoma, Bellingham, Mt. Vernon, Everett, and Olympia in Washington.
Western Valleys have a150- to 250-day season; warm days, cool nights; length of season may vary from year to year. Gardeners in the Rogue and Willamette valleys enjoy an excellent climate for gardening and a wide variety of fertile valley soils. Warm, sunny weather in late spring, summer and early fall provides good growing conditions with a minimum of garden plant diseases. Year-round gardening is possible, with mild winters where temperatures seldom drop below 20 degrees. Major agricultural crops include berries, vegetables, nut orchards, grapes, hops, grass seeds, Christmas trees, hazelnuts, and nursery stock.
Vegetable Gardening in Washington (Includes planting dates.)
Growing Fruits in Washington (Information about specific crops and methods)
Washington Vegetable Gardens (Information about specific crops and methods)
Seattle Tilth Website (An organization dedicated to creating a sustainable local food system.)
This paper by Oregon State University, includes information about gardening on the Oregon coast and valleys.