OP, 125 days spring sown/300 days fall sown. Walla Walla is the famous large overwintering onion from the Pacific Northwest with sweet, mild flavour and crisp, juicy flesh. It can be planted in the spring, but results will be better if planted in mid-late summer to overwinter. Walla Walla is hardy to -23°C (-10°F). Can also be harvested as tasty bunching onion. Not for storage.