Trebuchet Catapult Pumpkin Smashing Every year in the beginning of fall, pumpkin season is kicked off with an unusual past time. The pumpkin pitch. The pumpkin pitch's main component is a trebuchet, a medieval siege engine made to hurl objects long distances at high speeds. A pumpkin hurling competition is held each year on this date for trebuchets to compete in showing their skills. These trebuchet contestants compete in 3 heats to determine distance and accuracy.