Should I be afraid?.
It grows on a single stem up to six feet tall with no basal rosette and sends out runners replicating itself. I am pretty relaxed about what I allow to grow, usually leavIng visitors until I can assess whether or not I like the effect, and this one is attractive enough but I am rather wary that it might take over. I would be happy if it clumped up towards the back of the border (I like the yellow flowers) but the runners all head toward the front dwarfing smaller plants. It is while pulling up these wanderers that I have become concerned about the running underground stems.
Should I remove them before they set seed?
Thanks for your help.