I have done this in the past, but have forgotten when I divided them. I'm in the Pacific NW and my lungwort is almost done blooming (the bloom stalks are mostly all in a leggy horizontal plane rather than upright). As I recall, these plants kind of disappear by late summer. I would like to divide and move them now if it would not compromise the plant - I can see where some early blank spots are that need filling, and the majority of the garden is just waking up. Is now the right time? Or...? Thanks in advance.