My first and favorite perennial aster arrived unnamed from brother Tim from one of the gardens he was tending for an elderly woman. It has lavendar flowers in September/October and spreads generously. You don’t really remember it is there until the flowers start poking out among all the other plants.
The late timing of these perennial asters is a blessing in any garden or border. We have so few good flowers blooming in the autumn. I ended up adding a bunch of starts of various asters to the memory garden from a grower selling on eBay. I also ordered some hybrid asters from some mail-order categories. All of them are blooming now in October with very little else.
My future plans for these plants are to replace some of them with the native asters that will be a better match to local pollinators and plant eaters.