If someone had told you what a first-class baby-making machine the rose of Sharon (Hibiscus syriacus) is, you might have thought twice about planting it. Maybe you were drawn to the long-blooming rose of Sharon with its colorful, showy flowers that defy summer heat in U.S. Department of Agriculture plant hardiness zones 5 through 9. Maybe it was the plant’s alluring durability, carefree attitude and seductive promises to thrive on inattention and neglect. Whatever the reasons might have been, they’re now long-forgotten and drowning in a tsunami of rose of Sharon seedlings. Grab the kids and head outside for a plant-picking party.
Trim the rose of Sharon back in late winter or early spring with clean, sharp shears. Trim the stems back to leave only two or three flower buds on each. This helps keep the plant neat and compact. Rose of Sharon blooms on new growth, so pruning reduces the number of blooms you’ll get and increases the size of those that remain.
Hand-pull rose of Sharon seedlings as soon as you see them. Seal them up in a plastic bag and dispose of them in the trash. Don’t add seedlings to your compost pile, where they’re sure to take root.
Mow your lawn regularly to cut back any seedlings that hand-pulling may have missed. Repeated mowing will eventually weaken and kill the seedlings.
Clip flowers off the rose of Sharon daily as soon as they begin to fade. Deadheading extends the blooming season and prevents the plant from setting seeds. Pick up any blooms that may have fallen off the plant overnight. Put the flowers in the trash to prevent any mature seeds from escaping into your yard. Don’t toss them onto the compost heap.