Spots on Rose of Sharon
Although it would be nice to see a closer picture, I believe this is one of the cottony scale insects, maybe a Pulvinaria scale. They are soft bodied, with eggs under that cottony covering. Eggs will be hatching soon. You can wash with insecticidal soap and a strong stream of water from the hose, treat with horticultural oil, or call a landscape professional to treat. I suggest pruning the shrub before you treat, because there will be less in the way of branches and leaves to treat. It will stress the shrub but not kill it and may be worse one year than the next.
Thank you for contacting Cooperative Extension.