I live in southern new jersey, where the winters can be cold. I purchased several hibuscus this summer, which are doing well outside, but i know i will have to bring them in eventually. Last year i tried this and the plant did wonderfully throught the winter in the house, but when i put it outside in the spring it died. Any advise on what temp they should be brought in at, should i prune at that time? any specially instructions throught the winter? and what temp can they go back outside? thanks in advance for your wonderful advise!!