To the world, David Burpee was known as "the king of the seed catalogue empire," but his wife, Lois remembers him simply as Mr. Burpee.

"He was a very formal man, brought up in the old British tradition," she says.

When they met, she was a botany major in college, he a second-generation heir to the seed business. Burpee hired her in 1936 as a technical correspondent in the company's flower department, a topic she knew little about. So she spent her Saturday mornings study flowers at the 300-acre Fordhook Farms in Doylestown, Pa. "Occasionally Mr. Burpee joined me there," she would later write. "One day, quite unexpectedly, he proposed."

"It was certainly exciting when Fordhook was at its peak," she says. "There were 50 different kinds of lettuce growing at once. We'd sit at the dining room table and discuss hybrids."

Today, she says, it's more like a British homestead since the company pulled up roots and moved to California. The vegetable garden has shrunk to Lois Burpee's private stock, 100-by-100 feet. "In a way I wish all the activity were back, but it's kind of nice to let the dogs run without fear of them getting run over by tractors."

In its heyday, the farmhouse was a test kitchen that saw the likes of every hybrid that ever made it into the Burpee seed catalogues, and many that didn't. Lois Burpee began to analyze the flavors and uses of vegetables. "Whenever new vegetables were introduced, I tried to work out recipes that would enhance their color and flavor."

Simplicity is Lois Burpee's keyword when cooking fresh vegetables -- the focus of her book, "Lois Burpee's Gardener's Companion and Cookbook" (Harper and Row, $14.95). It was the culmination of a two-year project, that she began after David Burpee death in 1980.

Vegetables, she says, should be minimally cooked and enhanced with a light sprinkling of salt, pepper and one favorite herb, finished off with a pat of butter. "I don't mix my herbs [because] you get a jumble of flavors." For variety she suggests basic white sauce or sweet and sour sauce. Garlic, she says, overpowers most vegetables, although it works occasionally in salad. Some of her other tips:

* Freeze bumper crops by boiling the vegetables for two minutes, straining them, cooling under running water, straining again and freezing.

* Pick vegetables in the morning before afternoon heat drains their crispness. Store above-ground vegetables in plastic bags (do not wash them) and refrigerate. Rote vegetables must be washed, dried and stored in a cool place (such as a basement).

* Leaf vegetables (spinach, chard, lettuce) should be cooked the day they are picked, as brusided leaves turn brown.

* Let the crop determine the day's menu.

* Important fresh herbs that work well with vegetables are chives, parsley, basil, oregno, marjoram, savory, thyme and dill.

* Overcooking and letting vegetables sit in water drains the flavor and nutrients from fresh vegetables.

* Above-ground vegetables are delicate and tender and require close attention and a shorter cooking time than root vegetables if they are to retain flavor, nutrients and color.

*Freshness in the market can be determined by brightness of color, the number of bruises and appearance of the skin. TO COOK FRESH GREEN VEGETABLES

Put prepared vegetables in a heavy pot and pour boiling water over them to cover. Place on high heat so the water will return to the boil quickly. Add 1/2 teaspoon salt to 2 cups vegetables (4 cups of leafy greens). Leave the lid off; green vegetables lose their bright green color when covered. Stir them with a fork from time to time so that the cooking will be even. Taste. When they reach the right degree of doneness, remove them from the stove, drain completely and put them back in the pan over low heat to steam for about 1 minute to get rid of excess water. Peas and lima beans are best slightly moist, so do not give them the extra dry steaming. POOR MAN'S SAFFRON RICE

Pull petals from center of golden or orange marigolds until you have about 1/4 cup of lightly packed petals. Put petals on a cutting board and with a sharp knife cut them into shreds. Add them to 2 1/2 cups boiling water, 1 cup rice and 1/2 teaspoon salt. Return to a boil and then lower heat and cook for 20 minutes. Drain and season with butter. For more flavorful rice use chicken stock in place of water. BASIC WHITE SAUCE FOR GARDEN VEGETABLES

For a creamier sauce, use undiluted evaporated milk in place of the powdered milk and regular milk. 4 tablespoons flour 1/3 cup powdered milk 1 to 2 tablespoons butter, depending on fat in stock 1 cup cold milk 1 cup seasoned hot chicken stock

Mix flour and powered milk together. Melt the butter in a heavy pot or the top of a double boiler over boiling water. Stir in the flour mixture, then slowly pour in the cold milk, stirring constantly. Add the hot chicken stock and stir until thickened and smooth. Pour over cooked vegetables and serve, or set aside to reheat later. Do not cover the sauce or it will become runny.

If you like, add color and flavoring with an herb or finely chopped peppers. You might like a shake or two of white peper. Or you can stir in grated cheese. SPINACH AND ZUCCHINI (4 servings)

The last of my spinach and the first zucchini usually coincide, and that is when I prepare this dish. The pieces of celery and scallion should be smaller than the zucchini pieces. 1 zucchini, 1 1/2 inches in diameter 1 cup chopped cooked spinach 1/2 cup parboiled scallions, cut into 1/4-inch lengths 1/2 up parboiled diced celery 1/2 cup basic white sauce (above) 2 tablespoons seasoned bread crumbs 1 tablespoon grated parmesan cheese 1/2 tablespoon butter

Boil the zucchini whole until barely fork tender, then quarter it lengthwise and cut quarters into halves. Mix together zucchini, spinach, scallions and celery. Add white sauce in a double boiler and heat until warm. Turn into a flat baking dish, sprinkle with seasoned bread crumbs and parmesan cheese and dot with butter. Put under the broiler for a few minutes. SWEET AND SOUR SAUCE FOR GARDEN VEGETABLES

Red vegetables are particularly nice with this distinctive, grayish sauce. Experiment with spices until you get the flavor you want.

The basic sauce is made with cornstarch for thickener. Use 1 tablespoon cornstarch for each cop of vegetable cooking liquid. Add 3 tablespoons white vinegar and 1 tablespoon brown sugar. Add 1 tablespoon butter and salt to taste. Add allspice, cloves or giner as an artist adds color. Serve with cooked vegetables.