Freshly harvested garlic is easily damaged
image by Priya Hegde/sxc.hu
Harvesting garlic is a delicate process. Because fresh garlic bruises so easily, it's important to handle the heads with care when removing them from the ground. Additionally, garlic that is harvested too early will be undersized, while garlic that is harvested too late will lack most of the protective outer paper that keeps it from rotting quickly.
Keep an eye on the garlic after it has been planted. As bulbs of garlic form in the ground, thin green leaves sprout through the dirt. These leaves are a direct indicator of how well the garlic is doing; when they begin to brown from the bottom up, the garlic will be ready to harvest shortly.
Check the size of the garlic bulbs when the leaves are about 1/3 brown. To do this, use a digging fork to gently loosen the dirt over a bulb. Brush away the dirt with your fingers and inspect the bulb without removing it from the ground. If the bulb is tightly formed and about the size of a golf ball, it's ready to go. If it looks a bit small, replace the dirt and let it go a few more days.
Wait until the leaves are 1/2 to 2/3 brown if the garlic wasn't ready to harvest when you checked it the first time. At this point, the garlic bulbs must be harvested regardless of their size to keep them from going bad in the soil. Use the gardening fork to loosen the layer of dirt over the bulbs. Be careful not to pierce the bulbs.
Use your hands to clear the dirt away from the top and sides of the garlic bulbs. Slide a couple of fingers beneath each bulb and lift them out of the dirt. If the dirt is too hard to clear with your hands, use a flat spade to carefully dig out the bulbs. Never rip a garlic bulb from the ground by its leaves, as that could bruise it.
Transfer the fresh garlic bulbs to a dry, dark place immediately, as sunlight can burn the cloves. Brush the dirt off of the bulbs with your hands and trim away the leaves and roots.