Q.how do I get rid of rose of sharon seedlings?
I have plucked many of these seedlings out but, in some areas, they are so thick it is almost like ground cover. Is there anything I can spray on them to kill them? How can I prevent this from happening?
Unfortunately spraying will not work. Hand pull them as soon as they appear. Enlist the help of kids if you have them!
Seal the plants in a bag and dispose of. Do not put in the compost.
Mow the lawn regularly, regular mowing will weaken the the seedlings.
Dead head the mother plant and dispose of flowers so they can not seed.
You can also prune the mother plant in the early spring to reduce the number of flowers.
Here are a few links for you.