cutting back ironweed
Do I cut back Ironweed plants in the fall? I have a couple varieties. They seem to stay green. Also, do I have to wait till spring to prune back knockout roses?
Ironweed can be pruned back in the spring or early summer to control the size of your plant.
Allow the plant to die back naturally through the late autumn, then you can clean up the leaves now if weather allows or wait until spring.
Knock Out Roses also should be pruned in spring.