Growing fun: Michelle Obama’s Top 10 list on Letterman [Video]

First Lady Michelle Obama, promoting her new book about the White House kitchen garden, tested the range of vegetable humor on CBS’ “Late Show with David Letterman” with a Top 10 list of “Fun Facts About Gardening.”

It was Obama’s second appearance on the show, just months after she sat for a longer interview with Letterman. Her ongoing book tour has taken her to ABC’s “The View” and “Good Morning America,” as well as the “The Daily Show” on Comedy Central.

This time, she appeared on the late-night chat show via satellite from the Map Room of the White House, offering some deadpan jokes about what’s become one of the trademarks of her time as first lady, ending the bit by holding up a green “Barack-oli” – broccoli sprouting from a green likeness of her husband’s head.

Here’s the first lady’s full list:

10. Gardening was invented in 1822 by Albert Gardner.

9. Plant avocado, tomato, onions and cilantro together -- grow a guacamole tree.

8. Eggplants were originally cultivated for use as doorstops.

7. In a lifetime, the average American will eat half a radish.

6. The largest zucchini ever grown contained a Starbucks.

5. Later this year, the Supreme Court will finally rule on tomato versus tom-ahto.

4. If you have an actual green thumb, it might be scurvy.

3. Lettuce is 96% water and 4% lettuce.

2. The White House tool shed contains shovels, trowels and “Weed Whacker One.”

1. With enough care and effort, you can grow your own Barack-oli.