Demeter was the goddess of the harvest and was credited with teaching humans how to grow, preserve, & prepare grain. Demeter was thought to be responsible for the fertility of the land. She is also known for her fierce defense of her daughter, Persephone.
The Dark Mother, Demeter, represents this time of year. Mabon rituals welcome the Dark Mother, and celebrates that aspect of the Goddess which we may not always find comforting or appealing, but which we must always be willing to acknowledge.