Answer: The tropical hibiscus (Hibiscus sinensis) can be overwintered indoors. You can bring it inside and keep it as a houseplant or you can allow it to rest during the winter. If you want to keep it growing and blooming, bring it in before temperatures drop below 55 degrees. Place it in a very bright sunny location. It will go through an adjustment period but if the location is bright enough it may continue blooming during the winter. Protect it from hot/cold drafts, try to give it ample humidity, and be on the alert for pests.
If you do not have a good sunny place for it, wait a little later in the fall and then bring it into a cool place at about 45 degrees. Cut back on watering and do not fertilize. It will look shabby by spring, but should recover once it is back outside again.
In either case, rinse it well with the garden hose prior to bringing it indoors and consider treating it twice with commercially formulated insecticidal soap to try to prevent pest problems later this winter. Read and follow the label directions.
In my experience, these do best if kept outdoors as long as possible. You may want to keep it outside during the day when temperatures are still mild and bring it inside at night to protect it from cold to prolong the outdoor season for it.
In spring, put it out when temperatures are reliably in the 50's at night. Gradually acclimate it to being outdoors in the real sun, place it where it will recieve gradually increasing amounts of morning sun for about a week or two so it has time to adjust. Once it starts to grow again, resume regular watering and fertilizing.
Good luck with your hibiscus!
Q&A Library Searching Tips