It is grown in Texas and in Arizona. In Arizona, it is known locally as the “Grand Canyon Sweet”, and out of state, as the “Arizona Sweet.”
For some years, each May there was a “Grand Canyon Sweet Onion Festival” held in Rock Springs, Arizona, later being moved to Glendale, and then to Gilbert. The current status of the festival is uncertain.
Texas Grano 1015Y Supersweet Onions were developed 1972 to 1980 at Texas A & M University by a horticulturist named Leonard Pike, and released to growers in 1980. They were developed from the “grano” variety of onion, brought over from Valencia, Spain in 1925.
Part of the development goal was to make an onion more resistant to root rot than the original grano.
The 1015 in the name stands for the suggested planting date in Texas, 15 October.