Don't forget to add this bulb; you can use the Walla Walla, Maui, Bermuda or Vidalia variety
The same can't be said for the Vidalia onion, especially when... [DOC] [TLE] Sweet Onions (National Gardening Association) [PAR] 'Vidalia', 'Texas Supersweet', 'Walla Walla Sweet' ... sweet onions are ... Sugar 
levels really don't determine if an onion will be sweet.