Every year, the first warm days of spring cause me great anxiety. I don’t know what I am going to discover under the piles of leaves and dead foliage, and I always imagine that spring cleanup will be an exhausting and expensive task. This year, I promised myself I’d wait a few extra weeks before I began to remove last year’s stems and debris in order to offer beneficial insects and spiders a better chance of survival, but I can’t help wondering if I am also giving insect pests a great opportunity to survive and damage the shrubs and perennials. I have found that numerous perennials have already shed last year’s stems, so I feel comfortable gathering up the discards; it seems they have served their purpose and can be moved to the garden cart for disposal. The stems that remain attached can wait a few more weeks before being snipped and carried away. Most of these are native plants, including Joe-Pye weed (Eutrochium purpureum), boneset (Eupatorium perfoliatum), and great blue lobelia (L...