Rose of Sharon is a deciduous flowering woody shrub introduced to the United States from the plant's native origins in eastern Asia, India and China. Rose of Sharon are considered an invasive weed in Kentucky, Pennsylvania, Virginia and Tennessee.
Rose of Sharon grows a tap root capable of causing problems in the garden. Tap roots are substantial roots that extend deep into the ground directly beneath the plant as opposed to root systems known to spread out away from the plant. The deep tap root common to established 2 to 3-year-old rose of Sharon plants is difficult to remove should you choose to move or replace the plant.
Non-sterile cultivars of Rose of Sharon are prolific seed producers. Newly formed plants sprout from seed, establish tap roots and crowd out planned garden plants. Finding a continuous supply of unplanned plants makes the re-seeding and multiple tap roots problematic and invasive.
According to the U.S. Forest Service, sterile cultivars of rose of Sharon have been developed as an alternative non-invasive version of the popular plant. Cultivars Diana, Minerva and Helene mature to develop the deep tap root, but can't produce seeds.