What is the main reason for choosing to sow in Tomb-Sweeping Day instead of in winter?

Sowing in Tomb-Sweeping Day, not in winter, is mainly because the temperature gradually rises after Tomb-Sweeping Day, which provides a suitable temperature for seed germination. Qingming is one of the twenty-four solar terms and the fifth solar term in spring. When the sun reaches 15 degrees, the weather is fine. During the Qingming Festival, everything is obvious, hence the name. Qingming is a solar term that reflects the phenological changes in nature. At this time, the sun is shining, plants are sprouting, flowers are in full bloom, and nature presents a vibrant scene. In the south of China, the air is fresh and the scenery is beautiful. It began to snow in the north, the temperature rose, and spring blossomed.