What does *picked 'em up down South* mean?

Question

Came across:

It was Joey Hart, one of Mr. Martin's two assistants, who had explained what the gibberish meant. "She must be a Dodger fan," he had said. "Red Barber announces the Dodger games over the radio and he uses those expressions — picked 'em up down South." Joey had gone on to explain one or two. "Tearing up the pea patch" meant going on a rampage; "sitting in the catbird seat" means sitting pretty, like a batter with three balls and no strikes on him.

For context: this story

What does picked 'em up down South mean and why is a dash used before it?

Answer 1

The dash here acts like a colon: it indicates that what follows expands on or explains what precedes the dash.

Picked 'em up is spoken picked them up, meaning he “acquired” these expressions. Down South means in the southeastern part of the United States, which was in those days a largely rural part of the country and had many dialects which differed markedly from the rest of the country. The South is less rural today, the dialects are leveling, and the "colourful" expressions which were once rampant have largely disappeared; but you can still distinguish many Southerners by their pronunciation.

Baseball sportscaster Red Barber was a Southerner, and made his home in the South during the off season—the six months of the year when baseball is not played; and professional baseball teams did four or five weeks of 'spring training' in the South, where it was warmer; so Southernisms pervaded Barber's speech.