Depends on what you are fertilizing. Annuals and veggie crops I continue to fertilize until I rip them out for the winter. Permanent plantings, especially woody ones, you might want to at least cut back on. With a growing season of only 4-6 weeks left, I might consider once (maybe twice) more.

FWIW, in my mild climate and long growing season, I use a slow release fert (Osmocote) in very early spring on all permanent container plantings and a dilute water soluble only a couple/three times during the growing season. By this time of year I have pretty much stopped any supplemental fertilization on these containers, but continue the water soluble program on any seasonal container plantings.