Worldwide there are currently 559 varieties of garlic known, with cloves ranging in size from the size of peas to as large as your thumb. There are two species, commonly known as softneck and hardneck, and the types are further broken down by the configuration of the cloves.
Until recently, virtually all the garlic sold in America was California White. This is arguably the worst choice for "fresh" garlic. But it's the one the folks at Gilroy decided to use as their standard. The bulk of processed garlic---i.e., garlic powder etc.---still comes from Gilroy.
Now we import garlic from a number of other countries, including China, Mexico, Peru, and Argentina. Although some of the varieites exported by those countries are better choices, in terms of flavor and usefullness, there is no quality control. Result: An increasing incidence of bad garlic: rotted cloves, insect biten, inproperly cured, etc.
For restaurants and home cooks who grow their own gardens, garlic is a good choice. It's easy to grow. It's low maintainance. And, while it is subject to some pests and diseases, they are relatively rare (onions actually suffer more) and, in general, easy to control.
