Green roots sprouting from the center of the garlic clove are an indication that garlic has spoiled. The green roots have a bitter taste and should not be consumed.
Brown spots on the garlic cloves are another sign that the vegetable is turning bad. If the cloves have changed from white to yellow and tan in color, it is no longer fresh.
Garlic bulbs should not be refrigerated, but stored at room temperature. The garlic bulbs should be placed in an open container for the maximum shelf life.
Fresh garlic can last for 3 to 6 months when stored properly. Chopped fresh garlic should be refrigerated and will last up to 7 days.