Autumn bloomers refer to plants that flower in the autumn season. Two of the most popular autumn bloomers are MUMS (4 letters) and asters (6 letters). MUMS, also known as chrysanthemums, are flowering plants that come in a variety of colors and sizes. Asters are daisy-like flowers that come in shades of pink, purple, and white. Both MUMS and asters are popular choices for gardeners looking to add color to their outdoor spaces during the autumn months.