Rose of Sharon
This year my rose of sharon, I have four, didn't bloom like they did last year and the year before that. One of the rose, Lucy, did the worst. Lucy, the name/type of bush, bloomed early this year and then it begins to lose leaves like it's going into dormant stage for winter. Leaves turned yellow and hardly bloomed, maybe 5 blooms on the entire tree. Lavender Chiffon and one of the Blue Satin didn't even bloom, just made leaves. I recorded all the fertilizing and watering on all my plants. Everything in my yard bloomed except my rose of sharons. I live in zone 7.
You may have over fertilized. To much Nitrogen in the soil will cause lots of lush green leaves but no flowering.
You could do a soil test to take the guess work out.
Adding Phosphorous with a fertilizer like Bone Meal will boost flowering.
Here is a link to refresh you on care requirements.