When Dale approaches Peggy with a can of water chestnuts, we see her sprinkling ordinary table salt on the grass. In the winter, people sprinkle rock-salt, but on their sidewalks and driveways -not on grass! While this might be a joke about how little Texans know, Peggy is from Montana where it snows all the time. She should know a bit more about salting. If it was Hank then it might make more sense.