Hollyhocks self-seed. The seeds are so tiny and do such an efficient job of finding a place to germinate that they have to be controlled carefully. Additionally, there are now varieties that are much smaller than the old, standard 6 to 7 foot ones... Good luck...
wait for the flowers and stem to die completely before removing them. If you remove them too soon you run the risk of them not releasing the seeds, a bit like lilies.