By George E. Boyhan
University of Georgia
Many folks are confused as to what a Vidalia onion is. Some think
it’s a variety of sweet onions. And there are many varieties of
sweet onions.
A Vidalia onion, though, is really one grown in a specific
southeast Georgia region. The Vidalia name comes from the city in
the heart of this region.
The name Vidalia, for the purposes of marketing onions, is owned
by the Georgia Department of Agriculture. The GDA grants
permission to growers in the region to grow onions and market
them under this name.
The region where these onions can be grown encompasses 12 whole
counties and parts of eight others. Growers inside this “onion
belt” can grow and market Vidalia onions. Anyone outside can’t.
Federal, too
Besides the state recognition, there’s also a federal market
order for Vidalia onions. This gives federal recognition to this
region and its sweet onions. The market order also allows the
Vidalia Onion Committee to collect funds from growers for
marketing and research.
So, what about these sweet onions? What makes them so sweet?
To begin with, the type of onions is vital. Farmers in this
region grow short-day onions. All onions form a bulb (the part
you eat) as the days grow longer. Onions here form this bulb with
relatively short (11- to 12-hour) days.
Onions grown in more northerly latitudes are called intermediate
or long-day onions. As you may have guessed, they form bulbs at
even longer days. So, they’re planted in the spring and harvested
in summer or fall.
Short, sweet days
Because our onions bulb with short days, we grow them as a winter
crop. These short-day onions are known for their exceptionally
mild, sweet flavor.
Within this onion type, 25 varieties of sweet onions can be
officially grown as Vidalia onions. These must undergo three
years of University of Georgia testing before they can be
approved as Vidalias. The GDA makes the final decision for any
new varieties to ensure quality, mild, sweet onions.
Besides the varieties, southeast Georgia has the perfect
combination of weather, water and soil to produce Vidalia onions.
The winters are the perfect weather for onions: cool with not too
much freezing temperatures.
The region has plenty of irrigation water from large wells. And
water is critical to producing a mild onion. Without it, the
onions remain small and can be hot.
Finally, the region’s soils are perfect for onions because
they’re low in sulfur. Sulfur helps make onions hot. It’s from
the sulfur-containing compounds that onions develop their pungent
taste.
The bottom line is that this southeast Georgia growing region has
the perfect combination of conditions to produce the world’s
sweetest onions.
(George Boyhan is a Cooperative Extension horticulturist with
the University of Georgia College of Agricultural and
Environmental Sciences.)
