A lot of people don't realize that potatoes grow under ground. Same with garlic.
Garlic is planted just like an onion. You could get the stuff from the grocery store in the produce aisle but you are at the mercy of the farm it came from, unless you buy organic. Other options are from mail order catalogs or local plant stores. I got mine from my local Agway store.
The trick to garlic....plant in October and harvest in July. Yep that's nine months!!! It will get itself established and sit over the winter. By March or April when the ground starts to get warm it will start to grow. When the garlic stems die off and turn brown you can harvest. I was rather pleased with my harvest and it tastes MUCH better than in the store.
After harvest you can use it or dry it naturally in a warm dry location or use a dehydrator. If you dry it and then pulverize it, you have your own garlic powder! By the way, you can do the same thing with onions.
Here's what I harvested this year. I will be planting a bunch this fall.
Now go grow some garlic!!!