At Oliver Pecan Company in San Saba, where bins of different varieties tempt customers, Shawn Oliver is amazed at how little most people know about choosing pecans. "People think size matters," he says. "They'll come in here and get the biggest pecans, when I wouldn't feed those to our cows. Now, when they request Sioux, I know they know their pecans." Certain varieties mature as early as September, although pecans are generally harvested from October through February.