I seem to get mixed results for late planted vegetables, but the harvest is always varied enough and abundant enough to make the effort worth while.
Late squash and cucumbers most always give a reliable late crop until the first frost kills the vines. Some little boring cucumber worms seem to be active in the fall, but I almost never see them on the summer cukes. Just a small nuisance though.
Kale, collards, and arugula always start out well, but if the winter is too cold like last year, the kale and collards only produce for maybe half the season. Most years though all three produce an abundance of leaves from fall all the way into the late spring.
Of course the garlic goes into the ground in October or November. Will likely plant some in late September this year.
Parsley and coriander produce all through the winter, though the plants slow way down if the temperature gets too cold. We cheat and take the basil into the greenhouse and it usually produces an adequate number of leaves to carry us through the winter.
I would love to plant sweet peas and spinach in the fall garden, but I've never got them to mature. The spinach never wants to germinate. And the sweet peas will sprout and grow a bit, but produce no peas. Maybe I'll start some out in the air conditioned house a couple weeks early and move them into the garden in late September. Maybe they will then produce before it gets too cold.
Any one have any other suggestions for fall planted crops that would mature by late November or would over winter? Also, any one have a trick for getting spinach to germinate, or a way to squeeze a few sugar snaps off of the pea vines?