The location of tender plants is critical for their survival outside. There are some locations, such as low-lying areas, that will increase the risk. Large appliance boxes are good sources of protection, but today's gardeners have additional options that were not available for previous generations. Run cords with electric lights under boxes or other structures for a few more degrees of warmth. For the more serious freezes in the low-teens or colder, Winter said plants may need more than a cover.
Bubble wrap is one material that has shown insulating potential.
Wrap trunks of plants like palms and cycads to provide several degrees of protection in a vital area. Southern Indica azaleas like Formosa, G.G. Gerbing and Pride of Mobile are hardy down to around 10 degrees. Camellia japonicas can endure a brief drop near zero but will need protection if cold last for an extended period of time. Winter warned that shrubs still under drought stress will be much more vulnerable to the cold. The late summer drought is going to take a toll on many of our landscape plants.