Feb 08, In addition to reducing the height, you can cut out dead or diseased wood and remove any out-of-control branches back to the base. Because rose of Sharon blooms on the current season’s growth it should be pruned in late winter. Next winter, remove any new growth from the previous year and an additional third from the existing old treegrind.barted Reading Time: 3 mins. Jun 04, Bob Bricault, Horticulture Educator for Michigan State University Extension explains how to prune a Rose of Sharon using thinning and heading back cuts.
when can you trim rose of sharon bushes