THERE ARE ways to get vine-ripened tomatoes in the garden much earlier in the season, according to George "Doc" Abraham, author of garden columns for more than 100 newspapers and of seven books about gardening.

"Spray the flower clusters when they are open or partly open with blossom-set hormone spray, which comes in aerosol cans or in liquid form, ready for dilution," he says.

"The hormone chemical starts fruit development by chemical stimulation of the flower. Many of the tomatoes will be seedless, because the fruit is set by chemicals, not by pollen."

Abraham has a new book, "The Green Thumb Book of Fruit and Vegetable Gardening: How to Save Hundreds of Dollars a Year by Making Your Garden Work for You," published by Prentice-Hall, 354 printed pages, illustrated, $6.95, paperbound.

"Another way to produce more early fruit on tomato vines is to chill the seedlings," he says. "This is a new concept in planting. Studies show that flowering is stimulated in the tomato if the seedlings are exposed to cold.

"You get remarkable benefits by chilling the seedlings two or three weeks at 50 to 55 degrees F. (night temperature). This is done after seed leaves, or cotyledons first leaves to apprear unfold--and first true leaves have began to show--plants being 1 to 1 1/2 inches tall.

"Chilling the seedlings not only increases the flower numbers but results in early yields. Chilled plants are blockier (stocky), have thicker stems, and their survival following transplanting is greatly favored."

In his book, Abraham provides guidance and tips on every aspect of planting and cultivating a home garden.

"Our forefathers had one choice," he says. "Grow your own fruits and vegetables or starve. The art of raising fresh produce faded after World War II.

"And now the trend has changed. That's why this book was written. To stir up more home gardeners and get them back to the earth so they can reap the benefits of growing their own."

The book includes instructions on growing apples, pears and peaches, blueberries, raspberries and strawberries, nuts such as almonds, Chinese chestnuts, hickories, and pecans, how to grow them and eat better.

"Gardening is a good nerve tonic, good medicine for the mind and soul," Abraham says. "Doctors prescribe gardening to shake off frustrations and tensions. When you work in the soil, aspirin and tranquilizers are replaced by hard yet enjoyable work. You have a real chance to experience the outdoors and you'ss sleep better nights."

One of the big problems is the heavy clay soils, he says. A way to keep a clay soil in top condition is to avoid working it when it's wet. One day's work in a wet clay soil can make it hard the rest of the year.

Q. My vegetable garden soil is very poor. I can get a lot of sawdust. can I mix it with my soil to improve it?

A. Bacteria and fungi that rot sawdust, wood chips and shavings need nitrogen to function and they are almost certain to starve your vegetable plants by using all available nitrogen for their own growth. Even sawdust that has been available for two to three years could be detrimental to the plants you want to grow.

Q. Is it true that cutting off some of the small melons from a watermelon vine will result in the others being larger and of better quality?

A. You may get larger melons by reducing the number on the vine, but it is doubtful if quality (sweetness) can be improved.

Q. I planted crowns of Mary Washington asparagus last spring. Will I be able to harvest some this spring?

A. A small harvest is possible the next spring after planting, but don't overdo it. The next spring harvesting may continue for a month as stalks appear. Keep in mind that next year's crop depends on the growth made by the asparagus foliage this season. After harvest is over, cultivate shallow enough to control weeds and apply fertilizer, about 15 pounds of 8-16-16, or the equivalent, per 1,000 square feet.