Leave the Leaves
One of the most valuable things you can do to support pollinators and other invertebrates is to provide them with the winter cover they need.
While monarch migration is a well-known phenomenon, it’s not the norm when it comes to butterflies. In fact, the vast majority of butterflies and moths overwinter in the landscape as an egg, caterpillar, chrysalis, or adult. In all but the warmest climates, these butterflies use leaf litter for winter cover. Great spangled fritillary and wooly bear caterpillars tuck themselves into a pile of leaves for protection from cold weather and predators. Red-banded hairstreaks lay their eggs on fallen oak leaves, which become the first food of the caterpillars when they emerge. Luna moths and swallowtail butterflies disguise their cocoons and chrysalis as dried leaves, blending in with the “real” leaves.
Beyond butterflies, bumble bees also rely on leaf litter for protection. At the end of summer, mated queen bumble bees burrow only an inch or two into the earth to hibernate for winter. An extra thick layer of leaves is welcome protection from the elements.
Another reason to leave the leaves is for the many benefits they provide to your landscape. Leaves provide valuable organic matter and build up healthy soil. Fallen leaves have the same weed suppression and moisture retention properties of shredded wood mulch—and they’re free!
In the past gardeners may have worried that fall leaves, matted down by snow or rain, would have a negative impact on their perennials. In reality, a thick layer of leaves provides additional insulation against bitter cold weather, and can protect newly planted perennials when frost-heave may expose tender roots.
While the idea is to “leave the leaves” permanently – for all of the benefits mentioned above – if you do decide you need to cleanup the garden and remove the leaves in spring, make sure you wait until late in the season so as not to destroy all the life you’ve worked to protect.
Written by Justin Wheeler, courtesy of: