Hollyhocks should not be pruned in the fall, but instead in the spring season. After it has bloomed for the first time, the hollyhock should be cut in half anytime during the spring, and all blooms removed.
Hollyhocks must be allowed to bloom before pruning, which often does not occur until the second year. After the blooms have been removed and the flowers appear again, they should be pruned once more. This generally happens in the summer. The hollyhocks should be cut back to about 3 inches after the growing season in late summer. These biennial plants can provide several years of blooms if they receive the proper care. To protect them during the fall and winter seasons, the nearby ground should be covered with mulch.