Answer: It sounds like your rose of Sharon (Hibiscus syriacus) may have suffered some winter kill, which is common where temperatures reach 20F and below. Annual pruning is recommended to keep the shrub in top form and blooming well. It's best to prune in late winter or early spring. Prune the shrub to an open vase shape over the course of a few years, and each year prune branch tips back to a few buds. Frequent severe pruning gives fewer but larger flowers; little or no pruning gives many small flowers. You can prune off the dead branches at any time. Make sure your shrub gets water during dry spells, and it should bounce right back.
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