Hibiscus will backbud well pretty much anywhere. However they definitely have seasonal growth. In Southern California in landscape, mine throw two flushes of growth every year. They grow in the spring, then they stop in the heat of the summer, and then they will grow again in the fall, and stop in the winter. I actually have had best success trimming mine in the late summer after the dry heat has passed. This is when I do any hard pruning like full branch removals. The bush will push new buds and new growth and will flower profusely in the winter and early spring.
I would check your soil. It looks like clay and very fine and compact with no air spaces. My hibiscus do really well in an open high-organic mix like bark and rough cut peat.
Also... it is a bush that attracts white fly and aphids.