I bought Persicaria 'Dimity' from the VanDusen Perennial Sale last year. It flowered off and on all summer to fall, looked quite nice. However over winter the leaves have gone all brown and mushy. I looked at loosely pulling them off, but they are well attached, and new green leaves are coming up among them. What is the normal way to 'clean' the shrub up before all the new growth comes?
