"We're not just growing food, we're growing kids," says Guy A. Tinner, a 4-H Club worker. Clad in rubber boots, jeans and a bright yellow T-shirt, Tinner and several aides this week directed 15 children in cleaning an overgrown patch of land that will soon become an urban garden.

The children, students at Terrell Junior High School in Northwest, will learn to grow their own food in the middle of the city as part of an extracurricular school project.

"We decided to come out here in the hot sun and do a little work," said 15-year-old Rodney Yeager, leaning on a hoe and sweating not at all. Yeager's friend, Carl A. Edelen, 16, stood nearby laughing at his brother Kerry, who was struggling with a motorized tiller that behaved more like a bucking bronco.

Fourteen-year-old Rita Garey, the only girl, was more reserved. She stood aside with her hands in her pockets watching the antics of her classmates. But she was more than eager to give an impromptu lesson on how to cook collard greens -- one of the vegetables the children plan to raise.

The garden is sponsored by the Cities in Schools program, a pilot project at Terrell that works with government and private recreational and educational groups to provide activities for inner-city children and their parents. About 120 students now participate in a drill team, a dance group and a tutoring program set up as part of the project.

The garden idea came to John Shirkey, a planning agency employe working with Cities in Schools. He enlisted the help of the Department of Housing and Community Development, which located the 13,000-square-foot lot at the corner of North Capitol and Patterson streets NE, a few blocks from the school. The city lent the lot to the school for the project.

The 4-H Club was asked to lend technical assistance and earlier this week, several members accompanied the children on their first visit to the lot to get an idea about the task they were undertaking. They spent a few hours raking up papers, broken glass and a few discarded syringes.

The ground will be broken and readied for planting within the next two weeks. Crops will include tomatoes, carrots, squash, green peppers and eggplants. When the vegetables have matured, students will harvest them and take them home.

The 4-H Club is the youth branch of the University of the District of Columbia's extension services division. Reginald W. Taylor, state program leader for 4-H, says the project is designed to get the children outside and to help them learn to work together and develop a sense of responsibility. Parents have also been invited to help.

Taylor is confident the children will have fun with their garden, although he anticipates some good fights "when they start stealing each other's tomatoes."