Since her favorite color is blue, Emelie Tolley likes to slip bright blue borage blossoms into ice cubes to sparkle summer teas. With tricks like this and other notions described in a personal compendium on the cultivation and use of herbs, Tolley has blossomed into a popular figure in the world of horticulture. Since its publication last fall, Herbs: Gardens, Decorations and Recipes (Clarkson N. Potter, $30), lavishly illustrated with photographs by Chris Mead, has sold a remarkable 60,000 copies and is well into a third printing. "When people tell me it has advanced the cause of herbs 20 years, it's a big reward," says Tolley, "because that's what we were trying to do."

Tolley, 57, tells how to mix fragrant potpourris, assemble a treasure trove of dried wreaths, bake basil-flavored breads and produce chive-blossom vinegar, and her book is peopled with herb lovers. Cookbook author Craig Claiborne, for one, shows what tarragon can do for a steaming dish of veal meatballs, and Lady Caroline Somerset arranges a lush bouquet of delphinium, lady's mantle and gray lamb's ears in the stately drawing room of her English country house.

Tolley and Mead began collaborating in 1983 and spent two summers visiting close to 300 gardens in 15 states, as well as in England and France. Helpful friends scouted locales, although the two often stumbled by chance onto their finds, such as the trays of herbed chèvre cheeses charmingly set out to dry in a French barn.

Although a longtime gardener, Tolley's fascination with herbs didn't begin until a June weekend in 1980. Driving from New York, where she works as a free-lance color forecaster to the fashion industry, to her country house in Southampton, she heard a radio report saying that major food companies had begun to plant acres of herbs. Tolley had just started work on a cooking newsletter, but she quickly switched its focus. After six months and "an enormous amount of reading," she brought out Living With Herbs, now a 16-page bimonthly with a circulation of 2,500.

"Herbs are the in thing at the moment," says Tolley, noting that there has been a sharp increase in commercial growers (1,007 listed nationally, up from only a few a decade ago). "You can express yourself by putting basil with chicken instead of always using tarragon or by hanging lavender in the windows as curtains, which scents the room, is pretty and uses up the crop."

Tolley, who has never been married, grew up on Long Island (her father and grandfather were bakers) and went to the New York School of Interior Design before working for Glamour and Seventeen. She met the 36-year-old Mead in 1975 when they were working on the same audiovisual presentation for a furniture company, and the two have been friends ever since.

Tolley's book clearly benefits from the keen eye for detail she has developed in her 30 years in the fashion business. "Most people just see lavender as stalks of purple," she says, "but if you look closely, each one is composed of hundreds of little flowers that look like miniature orchids." Tolley wishes she had more time to work on her newsletter and to make use of her own recipes (such as nasturtium blossoms stuffed with herb cheese). But the book's success and the fact that there's a sequel in the works has, she says, "made me very happy." Perhaps her highest accolade was a glowing TV review from no less an expert than Julia Child. Says Tolley: "I felt that I had been knighted."