Foliage should begin to emerge in a month or so, and it can be harvested and used as you would chives. Each clove will eventually grow into a head of garlic. In March, begin fertilizing lightly every month until June, when the tops should begin to dry. Once the foliage begins to turn yellow, withhold water until it's completely dry, then harvest the heads. It requires full sun and fast-draining soil.
Several herbs make good groundcovers too.
Thyme is an excellent choice, as it's low-growing and tough and releases a wonderful fragrance when trod upon. It requires little water and grows well in full sun or partial shade.