Short-day varieties of onions such as the Texas Supersweet that are grown in the South take 80 to 95 days to mature from seed. Long-day varieties such as Spanish onions that are grown in the North take 105 to 120 days to mature. For areas with shorter growing seasons, onion seeds can been sown indoors and transplanted at eight weeks.
About this Author
Elizabeth McNelis has been writing gardening, cooking, parenting, and homeschooling articles from her St. Petersburg urban homestead since 2006. Her work has appeared in “The Perspective,” a homeschooling newsletter distributed in Pinellas County, Fla., and on her blog entitled “Whatever!” McNelis holds a bachelor's degree in professional and technical writing from the University of South Florida.