You really don't give any relavant information to help you with. It's like calling the docter and saying I don't feel good. Write me a perscription. They will play the 20 questions game to find out what the problem is before trying to fix it.

Where are they, in pots, in the ground, what kind of exposure, how do you and when do you water, are these the first hibiscus you've owned or are they the first hybrids, how often do you fertilize?

randy