September always throws me for a loop. It usually has pretty warm temperatures that keep you in the summer mood; but days are noticeably shorter, and the nights have just a touch of coolness to them. My garden at this point is overgrown, starting to die down, and a bit scraggly. I look forward to the blooms of aster and goldenrod to visually tear me away from the powdery mildew that is forming on the zinnias and the yellowing leaves of the milkweed. Both of these plants came to my garden on their own. Natives, if you will, have a tendency to find their own way into an open space. I do have to pull out quite a few in the Spring. Mid Summer, I give them a chop. This mid Summer chop helps keep the plants a manageable height and often helps the plant form side shoots to create a bushier plant with more flowering parts.
Other late bloomers that I welcome are Dahlias. I keep these tubers in the basement through winter and plant them each Spring. This could easily be their 5th year through the routine.
Cleome is a welcome self seeding annual. Also a late Summer bloom, it offers up a round appearance in the garden.
Consider adding any of the above to your garden next year. The pollinators will enjoy that late Summer pollen, and you will enjoy some late Summer color.