Michelle Obama's media blitz continued last night on David Letterman's Late Show, where she presented the night's Top 10 list, "Fun Facts About Gardening." The list included No. 7: "In his lifetime, the average American will eat half a radish," No. 4: "If you have an actual green thumb, it might be scurvy," and No. 1: "With enough care and effort, you can grow your own Barack-oli"—at which point the first lady held up a broccoli head carved into a likeness of her husband. The appearance was aimed at promoting her new book, American Grown: The Story of the White House Kitchen Garden and Gardens Across America, notes CBS.