Perhaps no other vegetable says summer better than sweet corn. Fresh ears direct from the corn patch are so much tastier and so much more appealing than corn prepared and served in any other way.

Corn is not new but the taste is. If you are still planting the old, standard sweet-corn varieties, you are missing the boat. Perhaps no vegetable in the recent past has undergone so many changes with so much improvement to the taste.

Although these dramatic improvements are most welcome, they have changed the way we grow the vegetable in our own gardens. In short, it is not your father's or your mother's sweet corn. Corn varieties are not all the same. If you've shopped for corn seed, it is easy to get confused by the initials on the packet or by the catalog description.

To help you understand them, here is the code. The initials "su" mean "normal" sweet corn. These old-fashioned varieties have kernels containing moderate, but varying, levels of sugar depending on variety. These sugars convert to starches rapidly after harvest.

The initials "se," "se+," or "EH" mean "sugar-enhanced" corn. Genes in this type modify the "su" gene, making the corn more tender and sweet. Additionally, the conversion of sugar to starch is slowed down so the corn stays good longer.

The initials "sh2" mean "super-sweet" or "extra-sweet." This shrunken gene ("sh" is short for shrunken) reduces the amount of stored starch but replaces it with more sweetness, and it also slows the conversion of the sugar to starch.

The newest type is the triple sweet. This latest development is a combination of 25 percent sugar-enhanced kernels and 75 percent super-sweet kernels. These are some of the best kinds I have ever tasted and represent some of the best kinds on the market today. Seed of this type are smaller and more shriveled. Honey Select and Serendipity are two superb varieties I tried last year.

Sweet corn kernels are yellow, white, or they may exhibit both colors on the same ear (bicolor). The sucrose (sugar) level in the kernels, not the color, determines the corn's sweetness.

One problem for growers is that sucrose is rapidly converted to starch if the corn is not cooked, frozen or refrigerated just after harvest. More starch and less sugar makes the corn less tender and less sweet. In these newer "sugar-enhanced" or "super-sweet" varieties, the starch conversion is much slower, so the ears remain better for much longer.

It is the ability to produce and retain this wonderful flavor that has revolutionized corn growing. It is no longer necessary to start the water boiling, run to the patch, pick and husk the corn, run back to the pot, cook the corn and eat it immediately.