Michelle Obama presents garden-themed 'Top Ten' list on Letterman

The first lady spoke from the Map Room in the White House as she gently mocked her vegetable-planting passion, sharing fake facts such as the origin of using an eggplant as a doorstop and the cause of an actual green thumb.

"Plant avocado, tomato, onions and cilantro together — grow a guacamole tree," said Obama, listing the No. 9 fun fact.

The Top 10 list didn't wade into politics, but No. 5 jokingly let viewers know that later this year the Supreme Court will finally rule on "tomato vs. tomahto." Obama also pointed out that the White House tool shed contains none other than, "Weed Whacker One."

And the No. 1 fun fact about gardening came equipped with a bushel of broccoli emblazoned with President Obama's likeness.

"With enough care and effort you can grow your own Barack-oli," said Obama holding up the faux broccoli, which included big, green ears.

Obama's first book, American Grown: The Story of the White House Kitchen Garden and Gardens Across America, was released last Tuesday and includes a large number of garden-oriented photos and recipes. All proceeds from the book go to the National Park Foundation.

Other recent "Top Ten" political guest presenters have included former presidential hopeful Gov. Rick Perry (R-Texas), making fun of himself for forgetting a third government agency he wanted to abolish during a debate, and the now-presumptive GOP nominee Mitt Romney, poking fun at his perceived stiffness on the campaign trail.