I planted this tiarella about a year ago. I have done nothing to it other than water it, no trimming or even deadheading. It seemed to take care of itself and stayed evergreen through the winter. This spring however, new leaves and flowetr stalks have sprouted up through the old leaves. I am wondering if I should trim the old leaves off from below or just leave it alone at this point. Obviously I'm clueless, new to perennial gardening, though I've grown vegetables for years.