According to the folk calendar - Mikhail Solomenny

On this day, all Orthodox believers remember the great Saint Michael, who at the end of the 10th century in Korsun baptized Prince Vladimir himself. This holiday is directly connected with straw, which was considered a source of strength; people slept on it, stuffed pillows with it, and fed livestock. Therefore, the main task on October 13 for everyone was to burn the old straw and fill all things with new straw or specially charmed field herbs.