After harvesting French breakfast radishes, Blythe Rients, 9, stoops to pluck dime-size toads from her garden plot.

"I think they give you warts," jokes John Zweber. "If they pee on you, you get warts."

She shrieks and flings the handful of tiny toads.

Kids take Zweber at his word regarding garden wildlife.

The master gardener teaches fourth- through sixth-graders each Tuesday evening at the Dakota County junior master gardener camp. Each budding gardener designs, plants, maintains and harvests a 6-by-7-foot plot at Rosemount's UMore Park.

Interest in youth gardening has grown in recent years, says state Master Gardener Program manager David Moen. He believes the trend reflects concerns about the economy and energy, as well as an increasing awareness of childhood obesity and food safety issues.

"I think it's kind of exciting because it's a great way to connect kids with life systems that are so much bigger than them," Moen says. "It's a wonderful venue for teaching a variety of things -- everything from life systems to science systems. Gardening is an exciting thing for young people."

Randy Seagraves, curriculum director for the National Junior Master Gardener Program, which began a decade ago, calls the White House kitchen garden a catalyst.

Both Seagraves and Moen say research shows kids who garden alter their food choices. "If they grow something," Seagraves says, "they will be more likely to eat it."

"It's fun to go outside," says Taylor Rients, 12. "When you're older, you'll know what to plant, how to weed... I've definitely learned a lot." She designed her garden primarily as a salad garden, and her photos of bugs and flowers earned a blue ribbon at the county fair two years ago.

"It's definitely a skill where, unless you have parents that do it, you don't learn it," says master gardener Sally Trojack. "The kids love it. They really stop to observe nature now."

This summer's 12-week course focuses on garden pests. Class begins when students assemble around a weathered picnic table to deliver reports on and discuss imported cabbage worm and powdery mildew. They also study spotted leaves and review key points of integrated pest management.

Then they tour a couple of the six-acre site's gardens, where master gardeners point out leaf curl caused by fungi and a screaming kildeer with a splayed tail protecting its speckled eggs.

Afterward, they weed, discuss individual garden issues and find spots for concrete "stepping stones" embellished with shells and colored glass pebbles -- last week's rainy day activity.

Class ends with a snack. Zweber pulls out a hand-crank food processor and whirls tomatoes, cilantro, onions and peppers into salsa.

"Each of the master gardeners can teach the children something different," says master gardener Dot Middleton. "John, of course, he's the best."

At times, the mentor-student relationship seems symbiotic.

"John, I noticed some problems," says Logan Middleton, 13. "You have slugs on your peas." A program graduate now in garden "grad school," Logan grooms his own raised plot on the other side of the grounds.

Madison Zweber, 8, has the answer for slugs: salt. "It shrivels up and goes into slime," she says.

The kids share bounty with the local food shelf, and, at the end of summer, enter vegetables, herbs and baked goods in the county fair.

"I love the harvesting," says Blythe Rients. "It's like a sense of accomplishment."

"It always amazes me when I see the looks on their faces the first time they dig up a radish they planted," says county Master Gardener coordinator Barbara Stendahl.

"You can see that light bulb go on. They are just amazed and delighted."

Liz Rolfsmeier is a Minneapolis freelance writer.