Since you can walk on perennial peanuts—as long as foot traffic is light—they're popular as a weed-suppressing groundcover or lawn alternative. Their small, pretty yellow flowers attract butterflies.

SOUTHAMPTON COUNTY, Va. — I caught up with farmer Elisha Barnes as he started his day pulling up peanut vines as the annual peanut harvest got underway. And he was pleased with what he found. “Oh, ...