Gladiolus Vs Hollyhock . The hole should be wider than the roots and deep enough to encourage the long taproot of bare root hollyhock plants to easily grow downward. Plant hollyhock roots in a prepared hole in the right location. Gladioli Corms Frizzled Coral at Suttons Seeds Gladiolus, Sutton from www.pinterest.com Remove and discard (not in compost) affected leaves. Allow about 2 feet between plants to allow for good air circulation; Cut back hollyhock stems to the ground after they begin to turn brown, but before they release seeds and multiply all over an area.