5214- Walla Walla. 110 days. Famous for its sweet flavor in fresh eating, Walla Walla is a medium to large mild onion with white flesh and light brown skin. Very cold hardy but not a keeper. Can be directly sown in mid-spring. Long day. Start indoors early, 12 weeks before last frost. Onions are very susceptible to damping off, so do not over water and keep the good air flow where you are growing your seedlings. Once onions are 3 inches high and about 1/4 inch thick, they can be brought outdoors to harden off.