The right time to bring the plant indoors depends upon the type of hibiscus you have. There are many species but three that are most common in our area. Hardy hibiscus hybrids are the large-flowered perennial ones that vary widely in size and are derived from Hibiscus moscheutos (rose mallow); they can survive outdoors in temperatures as low as -30ºF/ -34ºC. A potted plant will be less hardy and should be protected when temperatures reach -10ºF.

Hibiscus syriacus (rose of Sharon) has a woody stem and grows rapidly, reaching up to 15 feet in size. It can stay outdoors safely in the winter in USDA zones 5 to 8 and in temperatures as low as -10ºF./ -24ºC. Again, a potted plant is less hardy and should be protected at higher temperatures.

Tropical hibiscus (Hibiscus rosa-sinensis) is the most common houseplant or patio plant. These plants like to spend the winter indoors, in a cool room of about 55ºF./ 13ºC. and the process of acclimating them gradually to a space indoors should happen when night temperatures begin to dip into the 50's (F.). They will begin to slip into a two to three month winter rest at this temperature while they restore their energy and will need to continue to receive bright light. After a period of acclimation and during the rest period, give them only enough water to keep them from drying out. Once the winter rest is complete, return the plant to regular room temperature and a normal care routine.

Courtesy of NYBG Plant Information Service