One option is to use a floating row cover. This material is made of lightweight fabric that allows sunlight and water to reach the plants while still providing some protection from the cold. Another option is to use burlap or old blankets. These materials are effective at trapping heat, but be sure to remove them during the day so that your plants don't overheat. Whatever material you choose, be sure to monitor your plants closely so that you can make adjustments as needed. By taking these precautions, you can help ensure that your plants survive the cold weather.