Garlic is planted in autumn. It will take 6-8 months to grow, but is an easy and rewarding plant to grow. Though some people grow garlic from stores, some plants have been treated with sprout inhibitor so it’s best to get bulbs from a friend who grew it herself, or bulbs specifically sold as growing plants.
Plan to plant garlic in fall about four to six weeks before the ground freezes.
Prepare the soil by loosening it to a depth of at least 8" and mix in some slow-release, granular organic fertilizer.
Just prior to planting, break up the garlic heads into individual cloves, leaving as much of the papery covering on each clove intact as possible.
Plant cloves 3" to 4" deep, orienting them so the pointy ends face up.
Water gently to settle the soil, and then cover the bed with a 4" to 6" layer of straw. Even as air temperatures drop, the soil will stay warm enough for the newly planted cloves to establish roots before the ground freezes. Sometimes you'll see some green shoots form in fall; that's fine and won't harm plants. They'll begin growing in earnest in spring.
Next spring and summer, keep the bed weeded and watered.
As the harvest gets closer, keep an eye on your crop. The easiest way to know when to harvest garlic is simply to look at the leaves. When the leaves are one-third brown, you’ll need to start testing the bulbs to see if they are the proper size. This is easy to do. Simply loosen the dirt above one or two garlic bulbs and get an idea of their size while still keeping them in the ground. If they look large enough, then you’re ready to make your garden garlic harvest. If they’re still too small, then your garlic will need to grow a bit more. You can’t wait too long, though. Once the leaves get to be one-half to two-thirds brown, you should harvest the garlic regardless of size. Putting off harvesting garlic until after the leaves are completely brown will only result in a split bulb which is vulnerable to rot and so can’t be stored as long.