I need to trim down my Rose of Sharon. I never expected it to be so wide and tall in seven years! I would like to know when is the best time to trim down and how low or how high from the ground should it be trimmed down?
The Gardener’s Answer
Rose of Sharon (Hibiscus syriacus) are summer/fall blooming shrubs. As a general rule, we prune summer flowering shrubs during the late winter/early spring, but if your Rose of Sharon has any dead, diseased or crossing branches go ahead and prune now.
Otherwise, for shaping purposes and to reduce size, it is best to prune while they are dormant. Remove no more than one-third of the size of the plant each year. If you want it smaller continue to remove one-third each year until you’re happy with the size and then maintain yearly.
Rose of Sharon are large deciduous shrubs that will reach 8-10 feet tall and 4-6 feet wide. It sounds like yours is very happy where it’s growing. When you prune be sure to use rust-free, sharp pruners and remember that these are late to leaf out in the spring. Enjoy the blooms!