The frigid winter weather in the Midwest plays a vital role in sustaining the region's highly productive soil and supporting its native plant life. According to a blog from the University of Illinois Department of Extension Service, the cold air helps keep soil bacteria dormant, which is crucial for preserving organic matter levels that benefit both crops and gardens. This natural process is essential for the germination of specific seeds, such as milkweed and black-eyed Susan, which require a period of cold stratification to sprout in the spring.