My fall garden is pretty weedy but very colorful too. The purple asters come up as volunteers all through the garden and I pulled out at least a dozen throughout the summer. The volunteers are sometimes a different color so I have 3 colors this year. The sedum is really pretty right now too. I am glad I took a zillion pictures of the butterflies on them last year because this year I have only seen one butterfly near them.
This plant is another volunteer. I may have dug it out of the other garden last year and planted it here but I don't remember. It is as big as a bush and very colorful. You can see the neighbor's burning bush starting to turn in the background. Mine are still green.