(Image credit: Manuel Balce Ceneta/AP)

New faces and new potatoes marked the fourth annual spring planting in the White House kitchen garden this afternoon.

First lady Michelle Obama rolled up her sleeves and crouched down in the mud, working alongside three Girl Scouts from upstate New York to plant rows of potatoes, including five new varieties - purple Peruvian fingerling, red thumb, russet, mountain rose and sangre, and a small plot of mustard greens. They also sprinkled seeds for dill and cilantro on a dirt patch next to the sprouting garlic.

Around them, more than two dozen other school children worked in teams with hand tools and watering cans to plant carrots, onions, broccoli, swiss chard, cauliflower, lettuce, spinach, and kale.

"It's fun to live here," Obama said before the planting began. "It's fun, especially on a day like this because you guys are going to help us plant the garden, right? Yay!  It's so exciting!"

"A lot of times when you grow your own vegetables and fruits, they taste really good.  They taste better than a lot of stuff you'll get in a grocery store - trust me," she said.  "My kids have done it.  They're not big fans of all vegetables, but if they help to work on it they're much more excited about trying it out."

Before she arrived, the kids munched on apples and homemade granola bars on picnic tables near the White House beehives.

"It would take us forever to plant this garden if we didn't have your help, so it's really special to have you all here," she said. "So are you ready to do some work? Let's plant!"

It was the first time students from outside the Washington, D.C., area participated in the event, including groups from Fairport, N.Y., Ames, Iowa, Chester, Pa., and Greensboro, N.C.   All the invitees had written letters to the first lady about gardening and healthy living in their communities, the White House said.

With the exception of New York, all of the students hail from general election battleground states where the White House has been eager to attract media attention. The first lady also did sit-down interviews with anchors from local TV stations invited to the White House for the planting event.

Politics, though, did not seem to be on the minds of the students involved.

"We learned when you put down seeds, you don't just leave them there you put dirt on top of them to make them grow," said Keenan, of Sumner Elementary in Greensboro, N.C.

Classmate Makayla said meeting the first lady was a highlight. "It was cool. She's nice, she's beautiful," she said.

Obama began the garden initiative in 2009 to start a conversation about healthy living and the importance of fruits and vegetables, she said. It was the first vegetable garden planted at the White House since Eleanor Roosevelt's Victory Garden.

"We plant these little seeds, and you know these kids are curious about what happens. So when they come back in June for the next harvest, they get to see what they've put in the ground has grown," assistant White House chef Sam Kass, who orchestrated the planting, told ABC News. "They get to cut it and cook it and taste it. Today is that beginning. "

Kass said White House chefs use the harvested fruits and vegetables for the first family's meals, as well as for state dinners and other official functions.  About a third of the harvest is donated to a local soup kitchen.

"I'll come down and pick some spinach tonight that's left over from the winter planting for dinner," he said.