Pumpkin in a lace stocking. I've planted a bunch of mini white pumpkins. White lace stockings on them might be a nice outdoorsy Autumn touch. Inexpensive and kinda unexpected. These might be cute on the outside tables under the arbor too.
October is often the time for black and orange (and not only because La Crema is excited about a certain Bay Area baseball team! But plenty of non-traditional decorations also evoke this time of changing seasons and Halloween festivities.