Experts and BHG readers answer.
What to do with frost damage on tropical hibiscus
I'm sorry it's taken so long to get back to you. Our Q&A service was down for a few weeks for maintenance. Sadly, once tropical hibiscus have been hit by frost, it's tough to keep them going. Because they are tropical in nature, they can't tolerate frost. By now, I'm sure your plants are either dead or possibly limping along indoors. The most you could do is to cut them back and keep them in a very warm, sunny window for the winter to see if they recover. I generally treat mine as annuals because these plants are difficult to keep going indoors in the north.