Under the terms of Federal Marketing Order No. 955, as well as a state law, Vidalia Onions are defined to include only those produced in 13 counties and portions of seven others, all in Georgia. Although the yellow granex hybrid is grown in many other parts of the country, it is only in the defined production area that the soil and climate combine to produce the special characteristics of the sweet Vidalia Onion that has attracted the attention of gourmet taste buds everywhere.
Farmers plant Vidalia Onions from September through February. About 70,000 plants are produced on each acre.Approximately 225 growers cultivate Vidalias on over 10,000 acres.
Vidalia Onions flourish in the sandy loam soil and mild conditions – temperatures average in the mid-50s in the winter and mid-70s in the spring, with an average rainfall of 3-1/2 inches during the growing season.
Vidalias mature and are harvested from late April through mid-June. The delicate nature of Vidalia Onions requires that they be harvested by hand, thoroughly dried and treated gently during grading and packaging.
Recent technology has extended the marketing season of Vidalia Onions past the summer months by use of a process called Controlled Atmosphere (CA) storage. The principal characteristic of CA storage is a modification of the atmosphere in the storage facility. Normal atmosphere, or the air we breathe, contains about 79% nitrogen, 21% oxygen and .03% carbon dioxide. However, Vidalia onions can be stored for several months in an atmosphere of 92% nitrogen, 5% carbon dioxide and 3% oxygen, with the air temperature in the storage room being maintained at around 34 degree Fahrenheit.
No chemicals are utilized in the CA process, only the natural elements found in pure air. While in CA storage, the Vidalias remain dormant (virtually asleep) until they are removed and returned to normal atmospheric conditions.
Extensive testing has shown there is no change in the taste or texture of Vidalias that have been stored successfully for up to 6 months. This capability extends the marketing season into November and December which is ideal as Vidalias are have become a special part of many year-end Holiday meals!
The current CA storage capacity for Vidalia Onions is approximately 35 million pounds.
The Vidalia Onion Growing Region Map shows those counties that are licensed to produce Vidalia Onions.