I have two hibiscus in front of my house. Of course these die back every fall which leaves a whole in the landscape. I was thinking of using mums during the colder months. How should I do this?

Cut back the hibiscus before it dies off and plant the mums?

Wait until the hibiscus dies off naturally and then plant mums?

Will I need to cut down the mums next spring to allow the hibiscus to grow well? Will the mums come back next fall?

Thanks for any insights?