New gardening book is pick of the crop. With more than 200 authors, this just may be the definitive guide

``IT must have been a very meticulous and perhaps overly ambitious gardener who gave us the stern maxim: `To live off a garden, live in it.' '' So say the authors of Gardening: The Complete Guide to Growing America's Favorite Fruits and Vegetables. And gardeners, neophyte or experienced, who really want to understand their gardens might well spend much time living in this book -- which is exquisitely meticulous and is also successful in its considerable ambitions.

Four years in the making, ``Gardening'' comes as close as any book to being the definitive American work on its subject. It is published by Addison and Wesley in association with the National Gardening Association (NGA), which has its headquarters in this northern Vermont town.

The book has one author, the NGA, but more than 200 contributors -- all experts in their respective specialties -- drawn from around the country.

At $19.95 (soft cover) and $35.95 (hard cover) ``Gardening'' isn't cheap, but this quality production, with so much authority behind it, is worth every cent.

The 10-by-8-inch book boasts 325 full-color photographs and 160 drawings that illustrate crops, ideas, and techniques, as well as 70 maps and charts for easy reference.

It focuses on the 40 fruits and vegetables that repeated Gallup surveys, commissioned by the NGA, have shown to be the most favored in America.

Starting, literally, from the ground up, ``Gardening'' leads a reader through the minutiae of conceiving, preparing, planting, loving, nurturing, and harvesting a garden.

``Soil is more than just plain dirt,'' it says early on in the book. ``It is a dynamic mixture of mineral particles, living organisms, organic matter, air, and water that is the foundation not only of your garden, but of all plant life on earth. . . .

``The best way to get to know your soil is by working with it, digging through it, examining it, testing it, improving it. . . . Pick up a handful of moist soil and rub it between your thumb and fingers.''

From such homespun advice to highly detailed and technical instructions -- ``Side-dress corn with a fertilizer high in nitrogen such as urea or ammonium nitrate at the rate of about 2 pounds per 100 feet of row when the plants are 8 to 10 inches tall and again when the silks appear'' -- ``Gardening'' plows carefully and thoroughly through its subject.

The Gallup surveys indicate there is a ready and waiting audience for such careful research.

These surveys have shown that a new type of gardener has moved steadily onto the scene in recent years -- the young urban professional, well educated, affluent, and used to quality.

This gardening group of 30- to 49-year-olds has expanded dramatically, from 24 million households in 1983 to 29 million households last year.

These baby-boomers, with their ideals nurtured by the conservation movement of the 1970s, have matured into gardeners. They are motivated, according to NGA surveys, by a desire for fresher fruits and vegetables largely untainted by pesticides. They garden for fun, for the exercise it provides, and for the general sense of well-being that comes from such an activity.

With this audience for a comprehensive gardening book established, the NGA staff here in Burlington realized it had a resource that would be the envy of authors everywhere -- NGA's own experienced membership, along with a list of the names of every vegetable and fruit expert in the country, built up over years of publishing a monthly gardening magazine.

The group's staff members also sought out experienced home gardeners, along with recognized experts in horticulture and agriculture, to give the book more depth.

Gathering all the information was perhaps the simplest part of organizing the book.

Checking and rechecking the facts was another task altogether. So was crafting the language into a single writing style. Finally it all came together in a book that just about says it all.

Almost immediately ``Gardening'' became a Book-of-the-Month Club selection, and the Library Journal says it ``is very highly recommended.'' Bob Thomson, host of public television's ``Victory Garden'' and perhaps TV's best-known gardener, considers it a ``comprehensive and superb reference for both beginning and expert gardener.''

Best of all, in his opinion, it is up to date.

Robert F. Lederer, vice-president of the American Association of Nurserymen, describes ``Gardening'' as ``one of the best food gardening books available today,'' adding that a copy will go into his personal library, ``because it is just what every homeowner needs for his vegetable gardening effort.''