Hi,l Tobias, If necessary, it is best to cut back faded or dead foliage in late winter, or as the flowers begin to appear. Since they are in the midst of flowering, and it sounds like they need a bit of a taming, I would now wait until after they are flowering. I'm curious to see them - they are quite large/mature - any chance you could post a photo? Kathy C
I think that I have 3 large Plants, however unlike 'normal' hellobores these are flowering on the end of the leafy 'branches' which spread out from the base of the plant in a large(1m) clump. When should I prune these to stop them taking up all the border!