Sow True Seed Walla-Walla Sweet Spanish Onion Seeds

Walla-Walla Sweet onions are known for their ability to overwinter, but they are best suited for regions with mild winters. If you experience harsh, freezing temperatures, spring planting is the safer option to ensure a successful harvest.

These are not storage onions. Because they are bred for sweetness and high water content, they should be eaten fresh shortly after harvest rather than kept in a pantry for long periods.

Long-day onions require 14 to 16 hours of daylight to trigger bulb formation. They perform best in northern latitudes where summer days are longer, ensuring the plant focuses energy on growing the bulb rather than just leaves.

Yes, thinning is essential. While you start by spacing seeds 1 inch apart, you should eventually thin them to 3–6 inches apart once they are established to give the bulbs enough room to reach their full size.

While they prefer the depth and nutrient consistency of in-ground soil, you can grow them in containers if the pot is at least 8–10 inches deep and provides excellent drainage. Ensure the container receives full sun throughout the day.