It's the time of year for your houseplants, when they should be coming in from the outdoors and returned to the house. Almost all houseplants can withstand temperatures down to about 45°F (7°C), so keep an ear out for night time temperature predictions below 50° F (10°C). Then bring them indoors.
The week or so before bringing your indoor plants inside is a great time to get them in good shape for the winter. Repot any plants that have outgrown their pots over the summer, add potting soil to any plants that need it and clip off dead leaves.
While they are outdoors, give them a thorough soil soak, by using about three times as much as water as usual, and then let them drain. This process is known as leeching. Not only will that help the roots but can also help flush away any insects in the soil. Leeching helps flush out any salt buildups that that can build up over time from water deposits and fertilizer. This is a good practice to do anyway, every year or so, for all your plants.
When returning them to the indoors, be sure to place your plants in the best light that you can provide for your specific plant. That will help guarantee the best results over the winter.