Hello! Are you asking about the tropical hibiscus? Tropical hibiscus are only hardy in zones 8 and above. In the colder states we have to pot up our hibiscus and bring inside. Give them a sunny window or grow light. Here is a link that I hope you find useful!
Sincerely,
Acacius48

Here is a link that might be useful: Tropical Hibiscus Inside

I grow lots of tropical hibiscus inside, but the hardy hibiscus that die back each year and can be grown in zone 4-5 can also have beautiful flowers. Here are some pictures of hardy hibiscus from my yard.