The Texas Onion Fest on March 25 celebrates the development of the world famous Texas 1015 Onion which was developed in Weslaco and is also the State Vegetable of Texas. The name of the 1015 onion came from the suggested planting date, Oct. 15. Festivities include live entertainment on two stages, the Onion Eating Contest, food, commercial booths, kiddie rides, Dancing Horses, 1015 Market, Car Show, cooking demonstrations and more.