Garlic naturally produces seed heads on its flower stalks in the spring or early summer. To prevent seed production, most gardeners remove the seed heads when they appear.
Letting garlic produce seed heads on a stalk means it puts less energy into growth in other parts of the plant. Cut off the flower stalks if you do not plan on using the seed heads. Seed head production reduces bulb size by about one-third, according to Clemson University.
If the seed clove heads are going to be used for planting the next spring, break them apart only at planting time. Store them in a cool, dry place to ensure they produce multiple cloves in the bulb instead of a one large clove.