Garlic is generally planted in the fall and harvested in the summer. Garlic is ready to harvest when the lower leaves begin turning brown. Another sign that garlic is ready for harvesting is when the tops turn yellow and start falling over.
One way to find out if garlic is ready is by digging up a few bulbs of planted garlic and slicing them in half. Garlic cloves that are too small or do not properly fit the skins are not ready for harvesting. Garlic cloves should fill the skins without breaking them. Garlic cloves that burst out of the skin have been left in the ground too long and cannot be properly harvested.