Much is being written and spoken about “leaving the leaves” to provide critical overwintering sites for pollinators in garden beds. We’re in favor of this, but with some caveats.
Leaves blanketing driveways, walkways, and lawns DO need to be cleaned up, and the sooner the better. Plan to make use of these leaves elsewhere on site – they are a valuable resource that needn’t be hauled away. Use them as mulch on outlying shrub borders. Or shred them to use on bulb planting beds and areas where early-emerging perennials like primulas grow.
DON’T use blowers to blow away every last bit of vegetation (and mulch) from mixed borders of trees, shrubs, and perennials. Just as temperatures drop, it makes no sense to “bald” these beds. Instead, protect these plants and experiment with raking off only the topmost layer of leaves (if more than 6” deep) and leaving the rest until spring.
If blowers are in use, be mindful of where the leaves are blown. Map out zones of the property, such as edges, for possible use. Excess leaves are perfect for smothering a lawn area where you’d like to create a planting bed to install next year. Wet those leaves down as you place them to keep the wind from blowing them away! DO NOT deeply cover the stems of mountain laurel, low bush blueberry, and the like at the edge of woods that will quite literally have their roots smothered if too many leaves are stockpiled on them.
Perennial stalks that are cut now can be left to an 18” height, as the hollow stems can be used by overwintering beneficial insects. The green stalks will age in the winter weather and hollow out in the future. Experts such as Uli Lorimer, Horticulture Director at Native Plant Trust, suggest leaving this 18” stalk in place next spring, too, as the plant will quickly push up new growth around it.
Leave native plants standing whenever possible. Seedheads and stalks that may look messy now become more and more interesting with each frost. DO cut back non-natives such as hostas, daylilies, Shasta daisies, peonies, catmint, iris, and lady’s mantle as these do not have wildlife value. Also be sure to deadhead any standing garlic chives, as this plant seeds into other perennials in a pesky way and is difficult to remove.
Leave broken tree stems standing as snags for wildlife, as long as these plants are at the periphery and do not endanger buildings. Downed branches and twigs can be scattered at property edges or woven into a sort of fence line. Again, perfect wildlife shelter.