ALEXANDRIA, Va. (AP) -- First Lady Michelle Obama received a few gardening tips from students Wednesday as she toured a Virginia elementary school's vegetable garden.

Mrs. Obama and Agriculture Secretary Tom Vilsack visited Hollin Meadows Elementary to promote the Obama administration's Healthier U.S. Schools initiative.

Students showed the first lady how they harvested lettuce from the school's extensive garden that will be used in the salad at a special Thanksgiving luncheon later this week.

"We do the same thing in our garden at the White House," she said as they demonstrated how they dig up the lettuce by its roots and tap loose the topsoil.

The first lady has made an effort to promote childhood fitness and nutrition, installing a produce garden at the White House. Last month she hula-hooped on the South Lawn of the White house as part of a kids' health fair. The first lady joked Wednesday that the video of her hula-hooping has received "a little too much attention."

Mrs. Obama and Vilsack also passed out bananas and tangerines in the school's cafeteria line. She praised the school's efforts to promote nutrition as well as their decision to extend recess periods to promote fitness.

School officials explained that they extended the recess period from 20 minutes to 30 minutes a day, not only because it promotes fitness but because it helps the kids learn social interaction and leaves them more focused and engaged during classroom time.

"If anyone has kids, you know they need ... some exercise to focus," Mrs. Obama said. "If you have a dog, you know that."

Alexandria is just across the Potomac River from the White House. Students did not learn until this morning that the first lady would be attending. Fourth-grader Sydnie Vest was one of several kids who lined up to receive a hug; she said she didn't want to let the opportunity slip by.

"It was a special hug because that was probably the last time I'll ever be able to do that," she said.

Copyright 2009 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.