Over the years, I have learned something interesting about people and their container plantings. In the spring and especially during the summer, people are feverish about maintaining their pots. They are watered, fertilized, deadheaded, and adored. But by mid-August they get forgotten and are quite dead by mid-September. Should this have happened to you I highly encourage you to pull out the dead plants and replant with a new fall arrangement.
The garden centres bring in a whole host of new plants like chrysanthemums, ornamental kale and smaller sunflowers. This eclectic-landscape brightens up the verandah and uplifts the spirits for the brilliant leaf colours to come. The pots can also be further dressed up with pumpkins for Thanksgiving.
On another note, for garden maintenance, I usually recommend severely reducing the watering of the plants except where needed. The idea is to force your plants to start preparing for winter.