Cultivating a green thumb in the flower garden; Crockett's Flower Garden, by James Underwood Crockett. Boston: Little, Brown & Co. $24.95 in hardcover, $14.95 in paperback.

It was Jim Crockett's enthusiasm for flowers on his PBS television series, "Crockett's Victory Garden," that prompted me to dig up a corner of our yard several years ago and plant some marigolds.

That same enthusiasm for flowers continues to spill across the pages of his latest gardening book.Here we find poetic asides to budding sweethearts: "If the border were a musical, the annuals would be the chorus and the perennials would be the featured players. . . . And in my garden, Miss Lingard phlox would be the unquestioned star." There's plenty of rock-practical advice, too: "If a particular plant seems to draw hordes of insects or spends the summer with spotty leaves, we just don't grow it again."

Crockett was a greenthumb experimenter who wasn't afraid to change the way he transplanted seedlings and grafted roses from one season to the next. Before he passed on last year, Jim Crockett had a guiding hand in the design of "Crockett's Flower Garden," which is now being published by his associates. The book reflects a number of changes in gardening procedure from his previous work.

There are nine monthly chapters for gardeners on the go, and a chapter titled "After Frost" that covers indoor activities during the quiet winter months.

Though readers who buy the book now may have to wait until next year to actually grow the garden of their dreams (May is the month for care and feeding of 43 different annuals and perennials, and seedlings must be started even earlier), there are a number of things the would-be gardener can do during the summer. Not the least of these is to make a list, using the pictures from Crockett's garden of the plants you'd like to try -- foxglove, gaillardia, holly- hocks, Oriental poppies, Shasta daisies, and more.

Those are just a few of the 100 flowers that blossom in this book. They make for some 300 pages of stunning color photographs. Crockett's advice on each one has a lot to teach gardeners in all geographic regions of the US about propagation, cultivation, and pest control.

"Crockett's Flower Garden" speaks to the seasoned gardener in subtle tones of verbena varieties and salvia florets. A veteran gardener I know makes new "No kidding!" discoveries in practically every chapter.

As a beginning gardener, I'm just as fascinated, and of several recent titles I've bought or thumbed through on store shelves, Crockett's is by far the most complete.

Still, I sometimes need more hand-holding. My solution has been to team Crockett's timeless wisdom with the timely hints of Joan Lee Faust, garden editor of the New York Times. Miss Faust's "The New York Times Book of Annuals and Perennials" (New York: Times Books), published last spring, has just the kinds of pointers I occasionally need. When I was considering nasturtiums for a sandy corner of our yard, for example, I turned ot both sources. Said Crockett: "Once planted in the ground, nasturtiums need neglect." Added Miss Faust: "Soak the seed overnight in water to speed germination. . . ." Thanks to both, we're now expecting a fine red and yellow crop.