As bulbs finish blooming, I know that you are supposed to leave the dying foliage and not cut it off. What about perennials? Some spring and early summer-blooming perennials start to look tired by mid-summer; can you shear off their scraggly foliage?
Yes, you can trim back perennials, but don’t trim those that can give you winter interest in your landscape. Many perennials can be trimmed or deadheaded and will rebloom, while others die back naturally, like poppies and bleeding hearts. Leave the pruners in your pocket and enjoy Sedum, Rudbeckia, coneflowers, Astilbe, and ornamental grasses all winter long. In the winter months, the grasses will add texture and sound to the landscape and the others mentioned have lovely flower heads. If you must prune them, bring them indoors and make lovely arrangements for your home.