Walla Walla Onion Seeds - (Allium cepa)

Walla Walla Onion - The Sweet Heirloom from the Pacific Northwest

For over 125 years, a singular onion has become inseparably known with the small town in the Pacific Northwest, where it was first grown in the US. From the island of Corsica to the fertile fields of Washington State, the cultivar is legendary for its sweetness and flavor. These aren’t just any onions; they're deeply connected to the agriculture of this unique valley, a place where soil, climate, and dedicated cultivation combine to create something truly exceptional. When you slice into the creamy white flesh of one of these remarkably sweet, massive bulbs, it will transform your summer salads and grilled dishes with a flavor unlike any you've tasted; then, you'll understand why gardeners and cooks cherish this distinctive heirloom.

Details

The Walla Walla Onion impresses with its striking appearance and flavor. Its bulb, a slightly flattened globe, typically measures 4 to 6 inches and weighs up to two pounds, but in optimal conditions, it can reach an impressive 7 inches in diameter. The delicate, papery skin, ranging from pale yellow to light brown, reveals an exceptionally juicy creamy white flesh. This delightful sweetness, a result of its low sulfur content—about half that of a typical bulb—delivers a mild flavor that's a pleasure to eat raw. The texture adds a remarkably crisp, refreshing bite to any dish.

The bluish-green foliage, reaching 6 to 10 inches. A long-day onion, it thrives with 14 or more hours of sunlight, making it ideal for northern climates, yet it’s also adaptable as an intermediate-day variety, expanding its growing range. It matures in 100 to 125 days when grown from seed.

History

The Walla Walla Onion originated on the island of Corsica, off the western coast of Italy, where Peter Pieri, a retired French soldier, discovered a unique sweet onion variety. Around 1900, he brought these seeds to the Walla Walla Valley in southern Washington state. Here, he and his Italian immigrant neighbors launched a meticulous process of curation and refinement, focusing on sweetness, size, and shape. 

Over generations, they hand-selected the finest bulbs, resulting in the Walla Walla Sweet Onion. It has been carefully maintained through open pollination and selection, preserving its unique characteristics. Initially, it was referred to as the "French onion," but its unique characteristics earned it local recognition. "Walla Walla Sweet" gained widespread popularity in 1960 when Arbini Brothers Farms began shipping their onions to markets in the eastern United States. Caroline Arbini is credited with devising this now-famous name to differentiate her family's onions. In 2007, it was designated as the official vegetable of Washington State, partly the result of lobbying efforts that involved middle school students. 

Uses

Its exceptional sweetness makes it the star of raw dishes, but it also caramelizes beautifully, adding arich, jam-like sweetness to your cooked meals. Its inherent mildness and sweetness make it a star in fresh dishes like salads, salsas, and sandwiches, where its delicate flavor can truly shine. Thin slices add a refreshing crunch to a summer salad or diced into a vibrant salsa, each bite full of sweet, crisp flavor.

When cooked, its sweetness deepens, transforming into a rich, warm flavor that elevates soups, stews, and roasted dishes. Try caramelizing it for a sweet, savory topping or grilling it alongside your favorite meats, where the bulbs' sugars transform into a scrumptious, almost jam-like sweetness. It pairs wonderfully with fish, poultry, and a variety of cheeses, as well as an array of herbs and spices, offering endless possibilities. Whether you're layering it on sandwiches, mashing it with potatoes, or topping a pizza, the Walla Walla Onion adds a unique touch to every dish.

Companion Planting

Beneficial - cabbage family members, lettuce, tomatoes, carrots, beets, strawberries, and Swiss chard. Marigolds, chamomile, and summer savory are also beneficial companions.

Antagonistic - legumes like peas and beans, as well as asparagus and sage.

Planting and Growing Tips

For the best harvest, plant Walla Walla Onions in full sun, in loose, well-drained soil enriched with organic matter. Start seeds indoors 8-12 weeks before the last frost, sowing them ¼ to ½ inch deep. Alternatively, plant sets or transplants in early spring, as soon as the soil can be worked. Space plants 4-6 inches apart, with rows 12-24 inches apart. Ensure the soil temperature is between 60 and 85°F for optimal root establishment.

Planting in the fall for overwintering uses their impressive cold hardiness to your advantage. You'll harvest earlier, larger bulbs, often in late spring or early summer – a delicious jumpstart to the season. On the other hand, spring planting yields a summer harvest with slightly smaller, but usually sweeter, bulbs. This flexibility allows you to tailor your growing season and harvest to your tastes. You can choose the larger size for early summer grilling, or the concentrated sweetness for your mid-summer salads. For the best of both worlds - plant in spring and again in the fall!

Water consistently, especially during bulb development, keeping the soil moist but not waterlogged. Amend the soil prior to planting, and apply a balanced fertilizer at planting. Side-dress with a nitrogen-rich fertilizer every 3 to 4 weeks until bulbing commences, but avoid high nitrogen fertilizer after mid-July to ensure proper bulb maturation.

Harvest Tips

Harvest when the onion tops begin to fall over and turn yellow-brown, typically 100-125 days from seeding. Cure the harvested onions in a dry, well-ventilated location for 2-3 weeks, allowing the outer layers to dry and toughen. Store in a cool, dry place, away from potatoes, for up to 2-3 months. Refrigeration can extend their storage life. 

Learn More

• 3 Ways to Grow Great Onions From Seed
• Six Hour Caramelized Onions
• A Tale of Two Onion Soups

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