Garlic is planted in the fall – the same as ornamental bulbs like tulips and daffodils. In Southeastern PA, garlic is generally planted in mid-October. The timing is based on giving the bulbs time to create a good root system before cold sets in, but not so much warmth that they sprout before winter.
There are many varieties of garlic which fit into two main types, hardneck and softneck. Hardneck varieties are generally more hardy and easier to grow in our climate, but it never hurts to experiment. Garlic bulbs for planting can be purchased from many places where you would purchase fall bulbs.
Garlic bulbs should be broken into individual cloves and planted about 2 inches deep, 6 inches apart in an area with fertile, well-draining soil in full sun. Like other bulbs, your garlic will sprout in spring and grow through the beginning of summer. To get the largest bulbs, keep your garlic well fed, watered in times of drought and weed free. The flower stalks (or scapes) of hardneck garlic should be removed to maximize bulb size. They are edible!
Garlic is harvested when the leaves start turning brown. You want at least 4 of the leaves still have some green, otherwise the bulbs will split open, start to lose their papery wrappers and will not store well. Garlic is usually ready for harvest in our area by mid-July.
Harvest the bulbs carefully as they bruise easily when fresh. Allow them to dry for two to 3 weeks in a well-ventilated, shaded area. Then brush off any soil, cut off the dried tops and roots and store in a cool, dark location.
You can save some of your garlic bulbs to plant again next year. Save the largest bulbs to get the biggest crop.
Want more information? Here are a couple links:
Penn State Extension: Growing and Using Garlic
Penn State Extension: Garlic Production