If tomatoes are the movie stars of the kitchen garden  flamboyant, lush, sexy  then garlic is the charismatic character actor. Think of a Martin Landau or a Tony Shalhoub: colorful and Old World, yet somehow familiar.

How Old World? At least 5,000 or 6,000 years, Ted Jordan Meredith writes in “The Complete Book of Garlic.” Allium sativum probably sprang up from a crescent of Central Asia, perhaps north and west of the Tian Shan mountain range.

Garlic, Mr. Meredith explains, makes a cameo in the Bible, the Koran and the histories of Herodotus. You can read about it in ancient Sanskrit, and it was buried in King Tut’s tomb.

Spending a few millenniums in humanity’s kitchen garden has done some strange things to the garlic plant. For eating purposes, the bulb’s the thing. So gardeners the world over have tinkered with the parts of the plant that don’t generate a hearty bundle of cloves. Soft-neck garlic  the type we buy at the grocery store  rarely produces a flowering stalk. And hard-neck garlic, which does bolt, almost never creates pollinated seed.

Garlic’s “seed,” for gardeners, is the clove itself. We’re not talking about the shrunken, aged and possibly irradiated nuggets that fill a slop trough at the store. The good stuff, Mr. Jentink said, comes from the small-scale growers who fill the booths at garlic festivals. (This weekend brings the North Quabbin Garlic and Arts Festival to Orange, Mass., near Amherst, and the Easton Garlic Fest to Easton, Pa. The Connecticut Garlic and Harvest Festival visits Bethlehem on Oct. 9 and 10.)

A prime hard-neck bulb may be almost three-and-a-half inches across  the size of a chickadee’s body  and contain 4 to 10 hefty cloves. Connoisseurs and taxonomists divide garlic into 8, 10 or even 12 types, like porcelain, rocambole, purple stripe, silverskin and artichoke. Each offers a wide bundle of attributes, including flavor, heat, clove number, clove size and shelf life.