In Michigan, for fall flowers you might be limited to perennial chrysanthemums and the like. Check your local nurseries. Don't buy the chrysanthemums at the big box stores that have been forced to bloom out of season. They won't survive the winter. To get the "real thing" your real nurseries are the place.
Other plants like heucheras have a huge range of different foliage, and some change to beautiful leaf colors in the fall, though. Nice, small plants that are also perennial, and have pretty flowers in the spring as well.
