A PEACH may gain as much as 300 percent in flavor and sweetness during the last few days of ripening on the tree. A tree-ripened peach is far superior to those sold at markets, which are picked before they are fully ripe, as they must be so they don't spoil before reaching the consumer. Even when you go to a "pick it yourself" orchard, you seldom get tree-ripened ones.

And that's an important reason for growing your own if you have a place to do so. In addition to the high quality, a properly cared for fruit garden can save a lot of money. Of course, there is some work involved, but it need not be burdensome.

Several kinds of peaches and apples maturing at different times should be planted to prolong the season. All apple varieties require cross-pollination to get a good crop of fruit.

Most peach and nectarine varieties do not require cross-pollination. Like apples, the pear needs cross-pollination.

Tree-ripened apricots are a real treat. They are occasionally shipped to local markets from the West Coast but usually are picked at an immature stage, before full quality has been developed.

Whether you should grow pears is questionable because of their susceptibility to a disease called Fire Blight. Sweet cherries are usually for the birds: The birds keep a close eye on the fruit as it ripens and clean off the tree before you can take even a small share.

Birds go after strawberries, grapes, blackberries and blueberries, but netting or bagging can be used to keep them from getting all the fruit. Inexpensive netting can be purchased from large garden centers to put over strawberries, and grape bunches can be enclosed in bags.

Dwarf fruit trees are particularly well adapted for growing in small gardens where space is limited. A dwarf tree is produced by grafting or budding a desired variety onto a special type of root system (called the rootstock) that restricts or dwarfs the growth of the variety grafted upon it.

Dwarf varieties of apple, pear, peach, plum and apricot are available. The trees may be planted in the garden or on an open, well-kept lawn. They require full sunlight. Never plant fruit trees in a shady location.

Dwarf trees have these advantages: They begin to bear at an early age; they can be conveniently pruned and sprayed; small sprayers can be used for insect and disease control; the fruit is easily harvested, because no ladder is necessary; under favorable conditions the fruit is highly colored and above average size for the variety.

A pretty blush on a peach looks attractive but is not a sure sign of ripeness or good flavor. The background color is more important. It should be creamy yellow, though color varies with variety. Peaches may be yellow, yellow-blushed, red in varying amounts, white or white-blushed.

Tree-ripened peaches are those picked for eating within two days of maturity. They will be completely soft in two days at room temperature. Those picked at "firm ripe" stage will be ripe in three to five days. They can then be kept in the refrigerator for a few days. Place peaches only one layer deep in trays -- they may bruise when piled on top of each other.