Not much I think. Here's an excerpt from About.com
Rose of sharon blooms profusely, and its attractive flowers are its main selling point. Like other types of hibiscus, rose of sharon's flowers bear a striking stamen. Another feature giving the shrub value is its relatively late period of blooming (in the Northeastern U.S., it blooms in August). Rose of sharon is thus able to offer color when many shrubs have long ceased blooming. A heat-lover, rose of sharon is also prized by growers in the Southeastern U.S. who crave plants that can stand up to summer's heat. The plant is reasonably drought-tolerant. Don't give up on rose of sharon, thinking it's dead just because it hasn't leafed out by early summer. Rose of sharon not only blooms late, but leafs out late, as well.
at 6:22 PM on Oct. 3, 2010