The killing frost is always a very defining time of the fall season for me. The killing frost kills all soft annuals and some perennials. You can cover your plants but they will still freeze. The time below zero is too long and the frost will penetrate through covers you may have on your plants.
A week ago Thursday we had the killing frost. It went down to minus 6 (21 or 22 F). When I came out in the morning my tomato plants were black and all leaves were limp. They were toast! Impatience that were unprotected were frozen. One impatience right beside my house was fine. I had carrots, turnips and parsnips in the garden and they were fine as they can take lots of frost. If these plants have a god frost you find that they are sweeter and better tasting.
Once the killing frost is over with you can stop worrying about this event. You can quit watering and begin cleaning up the yard. So out go the tomato plants and impatience. Pull the carrots and bring them into storage. A few days later bring in the turnips and freeze them. I cook and bag them so that they are ready to pull out of the freezer, microwave and your eating. In a few more days I will dig up he parsnips. I slice the parsnips and freeze them. I like to fry them and find they are very tasty.
So once you're finished living in protecting mode you can get on with cleaning everything up. Sometimes we get many more pleasant fall days and have lots of time for fall jobs. Other years you have to pick your days and what gets done gets done and some of it will have to wait until next year.
So I look forward to some more pleasant fall and then the next defining moment is when the deep freeze and snow settle in for a more permanent visit.