Hi everyone. I live in Central Ohio (zone 5-b) and recently planted a Clifford Moor Catchfly. It is beautiful and has long stems with little pink flowers at the top. My question is, when these flowers are spent, do I remove the entire stem, pinch off the spent flowers, or just leave them be? I can't seem to find much info on this perenniel. Could any of you help? Thanks! Ellie