To be called a Walla Walla Onion commercially, an onion must by law be grown from Walla Walla strain onion seed, and be grown in the Walla Walla Valley. The valley lays partly in Walla Walla County in the south-eastern part of Washington State, and partly in neighbouring Umatilla County in adjoining north-eastern Oregon. As a home gardener growing the onions for personal consumption, you may buy the seeds and plant them wherever you like — you just can’t then sell them at your local market calling them legally Walla Walla Onions.
Walla Walla Onions have very brown skin and are slightly flattened on top. Inside they are white and juicy, with a mild taste. They can grow up to two pounds (900g) in weight.
The original strain takes 100 to 110 days to mature from seed depending on where you are.
Best eaten raw, don’t waste them on cooking.
Like most Sweet Onions, they don’t store well.
Walla Walla Onions were developed from an Italian/Corsican strain brought to Washington State from Corsica at the end of the 19th century by a man named Peter Pieri. This original strain is now called the “late French” strain.
Two newer sub-varieties include the Early Arbini, developed in 1925 by John (Giovanni) Arbini; and a third called the “Early French”.
Walla Walla means “many waters”.