DARRELL ANDERSON'S high school science students solved the problem of wild rabbits rummaging through their Rockville vegetable garden easily enough. They planted a wall of lettuce around it.

The bunnies spend gluttonous spring afternoons busily munching their way toward hundreds of pounds of tomatoes, peas, cucumbers, beans, sunflowers and watermelons. But they have yet to break through the lettuce wall. In fact, Anderson says, there's enough left over to feed the students at RICA (Regional Institute for Children and Adolescents) a few celebration luncheon salads and more to sell to the campus food services center. In return for these and other gardening efforts, the school treats Anderson's students to an annual free dinner and a night at the movies.

The gardening program began last year at the three-year-old residential treatment facility in Montgomery County for emotionally disturbed and learning-disabled students. Anderson has found that the 70-by-40-foot garden helps raise students' self-esteem.

"The students have gotten into it a lot more than I ever thought they would have," he says, adding that he's had to turn a few away. "The students gain respect for what they regard as their own work. They can make a commitment to this and follow through on it. While it's small, it's one they can't make anywhere else."

The bibb and boston lettuce varieties that they grow are the beauties of the patch. Their soft, floppy leaves form a flower-like head, similar to a large green rose. They taste light and buttery, hence their varietal name, "butterhead." Bibb is the more expensive of the two in the market and has more delicate leaves; boston is firmer with reddish brown edges on the leaves. Favorable soil conditions have made them the perfect lettuce for raising on the East Coast and they are just beginning to populate the marketplace.

Be wary of water-soaked heads when you buy lettuce. While a sprinkling of cold water will help firm up the leaves, too much will leave them soggy and wilted.

Store lettuce greens wrapped in paper towels in the vegetable crisper. Should you make them into a salad, be sure to add the dressing at the last possible moment, especially for the butterhead varieties as they tend to wilt and darken rapidly. Always tear lettuce leaves into bite-sized bits; cutting with knives will darken the edges.

Serve the freshest pieces torn into tiny bits on dark rye, pumpernickel or wheat bread topped with roquefort dressing or mayonnaise; or stuff crisp leaves with tuna, chicken or egg salad and roll them up like cabbage rolls. Lettuce also can be used to steam other fresh vegetables by placing diced pieces upon freshly rinsed leaves in the bottom of a pan. Encase them with a top layer of lettuce leaves and let them steam until the lettuce has released its moisture, about 10 minutes.

The soup that follows is a good way to use the all the vegetables just now coming out of the ground. (Substitute whatever looks freshest when you buy.) Add the lettuce at the last moment: the leaves will retain crispness and freshness, while giving a new dimension to soup consistency. The wilted lettuce salad is a popular old standby and tastes wonderful served with tiny slivers of hot Italian sausage. WILTED LETTUCE SALAD (4 servings) 1/4 pound bacon 4 hot Italian sausages 1/2 cup red wine vinegar 1 large or 2 small heads boston lettuce 1 cup chopped scallions, with tops Sprinkling of fresh basil, thyme or marjoram Salt and pepper to taste

Fry bacon and set aside to drain on paper towels. Cook sausages in bacon fat until cooked through, about 25 minutes. Remove, slice into 1/2-inch-thick pieces and keep warm. Discard all but 4 tablespoons of drippings from the pan and reheat. Add vinegar and bring to a boil. Wash lettuce leaves and pat dry. Put lettuce leaves, scallions and sausage pieces in a bowl. Sprinkle with fresh herbs, salt and pepper. Pour enough hot vinegar mixture over salad to your taste, and toss. Serve sprinkled with bacon bits and whole sausages. SPRING VEGETABLE SOUP (6 servings) 3 1/2- to 4-pound chicken, cut up 1 rib celery, cut in thirds 1 carrot, cut in thirds 1 onion, stuck with 4 cloves 1 large clove garlic Salt and pepper, to taste

For the soup: 4 tablespoons butter 3 tablespoons flour 3 small turnips, peeled and cubed 1/2 cup fresh peas 2 carrots 2 cups fresh asparagus, cut into 1/2-inch pieces 2 cups fresh spinach leaves, coarsely chopped 1 small head boston lettuce (about 2 cups) 1 cup heavy cream Salt and freshly ground pepper

Place chicken, celery, carrot, onion and garlic in a heavy saucepan and cover with 7 cups cold water. Season with salt and pepper. Cover and cook through (about 25 minutes). Remove chicken and strain. Set broth aside, keep warm and store chicken for another use.

Melt butter in saucepan; just as bubbles begin to subside, add the flour and whisk to smooth sauce, about 2 minutes (be careful not to let the flour burn). Remove from heat and add 6 cups of warm broth and whisk until smooth. Return casserole to the heat. Bring to a boil, whisking constantly, and cook until the soup is thick and smooth.

Add the turnips, peas and carrots and cook until barely tender (about 10 minutes). Add the asparagus and cook 5 minutes more. Add the spinach and lettuce and cook until barely wilted (about 30 seconds). Add heavy cream, stir and taste for seasoning. Serve immediately. Adapted from "From Market to Kitchen Cookbook," by Perla Myers