This is perhaps the most well-known of the sweet onion varieties. It was first grown in Toombs County, Georgia, but it came to Georgia from Texas. It is by law grown only in thirteen counties and portions of seven others in southeast Georgia. The soil and climatic conditions in these defined areas combine to produce the sweeter granex hybrid trademarked as Vidalia onions. The city of Vidalia was the site of a Farmer's Market since it was located at the junction of several heavily-traveled highways. The sweet granex onion came to be called after this hub city. Vidalias are harvested from late April through mid-June, and thanks to controlled-atmosphere storage, they are available through December. The Vidalia onion is a light golden-brown bulb with a white interior, rounded at the bottom and somewhat flat on the top stem end.
The grandfather of this variety was the grano, originally imported from Valencia, Spain in 1925. The 1015Y variety was developed at Texas A&M University as a strain which was more resistant to pink root disease than the Grano varieties. Prime time for Texas 1015s is April through June. It derives its name from its ideal planting date, October 15. Horticulturist Leonard Pike is responsible for isolating the tear-causing chemical pyruvate and decreasing its presence to result in the sweet 1015. This variety can grow to softball-size, with optimum size being 3-4 inches in diameter. Its single-center design makes it a perfect candidate for fried onion rings. From the university home of the 1015, this small recipe collection includes a fool-proof recipe for onion rings.
Named for the Washington city, these sweet onions originated on the Island of Corsica off the west coast of Italy. The seeds were brought to Walla Walla (Native American for "many waters") in the late 1800s. Law also controls the marketing of Walla Walla Sweet onions, which must be grown in a specified area of the Walla Walla valley to claim the name. This variety is available from June through August.
Other Sweet Onions
Imperial Sweets, derivatives of of the grano and granex varieties, are grown in the Imperial valley of California, and are available from late April through early June. Oso Sweet onions hail from South America and are said to contain fifty percent more sugar than Vidalias. Osos are avaliable from January through March. Maui Sweets come to us from the Hawaiian island of the same name and are available from April to July. Other varieties may also be marketed as Bermuda sweet onions. Some Italian Red varieties are also mild and sweet enough to join this category, but simply choosing by the characteristic deep red-maroon color will not always guarantee a sweet onion. Red Italian onions are usually used raw and are an excellent choice to give a color boost to salads and sandwiches.