Pruning Rose of Sharon

On Cape Cod many grow, and love, their Rose of Sharon shrubs, Hibiscus syriacus. They are a favorite late-summer bloomer with single or double flowers in shades of pink, white, lavender or blue. This large-growing, upright shrub is often used in mixed shrub borders and privacy plantings, or in foundation beds where they can grow tall and wide. But many people don’t appreciate how some Rose of Sharon self-seed, and they get tired of weeding the young plants out every spring.

Fortunately, you can combine pruning with deadheading on this plant, which encourages bushy growth and gets rid of the seed pods at the same time. Because Rose of Sharon blooms on new growth every year, you can prune it in the fall without influencing the flowering.

This is the time of year to prune Rose of Sharon, and get rid of the seed pods at the same time. Cut 6 to 12″ pieces off of each stem, and dispose of these so that the seeds won’t be able to sprout in your yard or compost pile. (I dry mine in a paper bag and then burn them!)

Cut some of the outside branches down lower than the ones in the center, so that growth is encouraged over the entire plant. Shaving it all off the top results in a shape that’s not natural, and promotes all new growth at the top and not on the sides. This type of pruning cut is called a “Heading Cut” and double growth is stimulated right below where you make that cut. To learn more about pruning all types of shrubs and trees, register for the Sunday Seminar on September 26th.

You might need a ladder to reach the tops of a high Rose of Sharon. Some hire a professional to prune extra-large plants. One question our customers frequently ask is “How much can I cut it back?” The reality is that you can cut as much as 1/2 of the total size, but that isn’t going to keep the shrub small, and it is likely to look “hacked” and not as attractive for a couple of years. If your Rose of Sharon is too large for the location, it might be best to move or remove it.