The optimal period for setting garlic cloves in Zone 6 is typically during the fall, specifically from late September through October. This timeframe allows the cloves sufficient time to establish a robust root system before the ground freezes. Successful root development over the winter is crucial for producing large, healthy bulbs the following summer.
Planting during this period in Zone 6 offers several advantages. The cold weather helps vernalize the garlic, a process vital for bulb formation. Furthermore, planting in the fall avoids competition with spring weeds and allows the garlic to capitalize on spring rains and warmer temperatures for rapid growth. Historically, fall planting has been the standard practice for maximizing garlic yields in regions with cold winters.