Onion Walla Walla

Onion Walla Walla

Growing Tips: Onion Walla Walla

Quick Reference:

Plant seed 1/4 inch deep spaced 1 to 2 inches apart. Germination: 10 to 20 days. Plant spacing in the garden, 5-6  inches. Shallow planting provides warmer soil but soil MUST be kept moist at all times until plants emerge.

When and where to plant:

In Alaska, start seed indoors 8-10 weeks before last frost date, to ensure healthy transplants. As seedlings grow, trim tops to 3 inches to grow sturdy plants with strong root systems. As the get closer to transplanting, let them get 4-5 inches tall. Trimmings are edible for use in salads and soups. When transplanting, handle carefully and tease plants apart, taking care not to damage roots. Although cold tolerant, onions must be hardened off before planting in the garden. Plant in fertile, well drained soil in a sunny location. Use compost to improve clay or sandy soil. Plant in any pattern you wish, with roughly a hand span between plants or plant in a furrows, using an organic or timed released fertilizer. Works well in raised beds.


Keep soil consistently moist until bulbs enlarge. Onion roots are shallow, so apply a light layer of mulch to slow evaporation. Once bulbs push through the surface, remove the mulch to allow them to bask in the sun.


Pull onions at any stage for fresh eating. For full sized onions, wait until bulbs are large and tops start to yellow and fall over. Pull onions, shake off soil, and cure in a warm, airy place before trimming tops and roots. After 7-10 days of curing, during which time the roots shrivel and necks dry and tighten, clip tops and roots and rub dry dirt from bulbs leaving papery outer skins intact. Walla Walla onions only last for a few weeks. They are best stored in the refrigerator.