Texas Grano white onion seeds are a type of short-day open-pollinated onion variety that features white flesh and straw-colored skin. They are known for their mild and sweet flavor and even white texture. They usually grow well in temperatures between 55°F-75°F and do best in rich, moist soil. Growing Tips: Usually started indoors 8-12 weeks in advance of planting out, typically 3-4 weeks ahead of last spring frost. Does best in rich, moist soil. These extra-sweet and early Vidalia-type onions have a thin skin and supremely mild flavor, so sweet they can be eaten like an apple. The onion bulbs have thick scales and sweet white flesh.