I usually prune my off in the early spring when I see new growth starting. This is a beautiful plant. I have 'Blue Fortune' and 'Golden Jubilee'.
My question is about height control. The 'Blue Fortune' is gorgeous but it gets a little bit too big and totally covers up the blanket flowers and yarrow next to it.
Is it possible to prune or pinch this for height control? If so, when and how?
Here's a picture of it last month.