White House chef Sam Kass directed the effort, which took place on a sunny but cool afternoon on the South Lawn of the White House.

"Where are your jackets?" Obama asked the kids, who wore a variety of colored T-shirts with "The Presidential Garden Project 2013" written on the back. "I'm gonna be a mother," she added.

It's the fifth year she's invited school children to help with the project. One new plant added this year was wheat, said Kass, noting it was picked because a lot of bread was eaten in the White House.

Kass was discreet about the first family's eating habits. When asked what President Obama's favorite vegetable is, he said: "He doesn't have a favorite vegetable. He likes them all."

He also noted that presidential daughters Malia and Sasha eat "whatever they're served."

One plant missing from the garden was beets, which neither of the Obamas like.

The first lady told ABC News last year that "one thing the president and I, we don’t really like, are beets."

After the planting was done, the kids snacked on apples, which Obama has said are her and the president's favorite snack.

The first lady — dressed in sneakers, gray and white print pants, a bright yellow shirt and a gray and white stripped jacket — signed the kids' shirts before she left and gave them all hugs.

Students were chosen from schools that made improvements to their lunches through the Healthy, Hunger-Free Kids Act. They came from Florida, Massachusetts, Tennessee and Vermont. They were joined by students from the local Harriet Tubman and Bancroft elementary schools.

Photos: (Above right) White House Chef Sam Kass and first lady Michelle ObamaMichelle LeVaughn Robinson ObamaObama on social media: You’ve got to ‘think before you tweet’ MSNBC trolls Trump with video montage of Obama saying ‘Merry Christmas’ Overnight Regulation: USDA delays healthy school lunch requirements | Senate panel advances controversial environmental pick | Drone industry pushes to ease rules | Dem commish joins energy regulator MORE get ready to plant wheat seeds. (Above left) Obama and kids planting.