Alright, as much as I hate to think about it, we should be planning for a late freeze to take place this week. I blame the weather men and women. Obviously, they did not do the correct interpretive dance. So, plants are money. Let's talk about ways to protect them.
1. Hanging Baskets-Place them in a garage or shed. If they can't be put there, place on the ground, water, and cover.
2. Water EVERYTHING. Focus on saturating the soil over the foliage. Professional growers have specific ways of protecting plants by wetting the foliage. I don't recommend this for the average Joe.
3. Chances are most of your flowering containers, Summer vegetables, and herbs will need to be covered. Even plants that are not normally cold sensitive should be protected if purchased recently. They may have been grown in a hot house, and they've not had a chance to harden off.
Give them a good drink of water and cover them with burlap, sheets, or towels. Not plastic. Secure the edges on the ground so that wind will not destroy your efforts.
4.Get out your strings of lights! By trimming your plants, you can protect them. The lights will raise the temperature. Follow these safety tips: use outdoor cords and lights, don't let hot lightbulbs sit on foliage or sheets, and be sure to undo all of this the next morning. Check out this LSU page on protecting citrus.
You may not be able to get row covers by this point in the game, but I'm posting this video to give you an idea of how to cover your garden. You could make the hoops out of something from the hardware store. Creativity saves the day!