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In the last month, we wrote about how to turn piles of fallen leaves into compost to turn fall bounty into spring and summer garden glory. There's another reason to reconsider neatly bagging every leaf and cutting every stem. You can provide critical habitat to overwintering insects that local ecosystems desperately need. Leaving strategic piles of leaves beneath shrubs and letting flower stalks stand through winter can lead to a somewhat "unkempt" yard that will buzz with life -- pollinators emerging from chrysalises, beneficial beetles crawling from leaf litter and songbirds feasting on the abundance of insects their messy garden protected.
With autumn cleanup season in full swing, property owners face a choice that ripples through their entire food web. The decision to "tidy up" a yard isn't just about aesthetics -- it's about whether next summer brings native pollinators to your flowers, whether chickadees find enough caterpillars to feed their nestlings and whether your garden ecosystem thrives or struggles. The good news? The lazier approach -- doing less fall cleanup -- is better for biodiversity, easier on your back and free!
Leave leaf layers in garden beds. Instead of removing all your fallen leaves, rake them into 4-inch-deep layers in your flower beds, around the bases of trees and shrubs, and in any areas of your yard where you don't need to walk. These leaf piles provide crucial overwintering habitats for countless beneficial insects. The nine-spotted ladybug spends winter as an adult beetle in leaf litter, while walking stick insects (phasmids) drop over 100 eggs from trees that must overwinter in leaves to survive. Luna moths -- those spectacular pale green beauties -- overwinter as pupae in cocoons disguised to look like dead leaves. Great spangled fritillary butterflies lay eggs near violets in fall, and the tiny caterpillars that hatch need leaf cover to survive until spring, when fresh violet leaves emerge.
Many native bees, including bumblebee queens, depend on leaf litter for winter insulation as they shelter in loose soil or rotting logs. Without adequate leaf cover, these pollinators cannot survive harsh winter conditions. These aren't just "bugs" -- they're a foundation of your local food web.
Those dead flower stalks you're tempted to remove? They're apartment buildings for native bees. Many species of mason bees and leafcutter bees overwinter as larvae inside hollow stems of plants. Swallowtail butterflies attach their chrysalises to standing stalks. If you must tidy your garden, cut stems to at least 8 inches high rather than at ground level, giving stem-nesting insects safe homes.
Create a designated "wild zone." Even a small corner of your yard left intentionally messy provides disproportionate benefits. Pile leaves raked from walkways and driveways into these areas. Add fallen branches and twigs -- mourning cloak butterflies overwinter as adults in wood piles and between loose bark. Many lacewings and lady beetles (which devour aphids in summer) seek small crevices between rocks or wood for winter shelter.
Understand what you're protecting. Ninety-six percent of terrestrial bird species rear their young on insects, and caterpillars are the most critical food source. A single clutch of chickadee nestlings requires over 5,000 caterpillars to fledge successfully. Research shows that chickadees strongly prefer to forage on native trees over non-native species. When you think about protecting overwintering insects, think about protecting the entire food chain, from soil invertebrates to native plants to the songbirds that brighten your mornings. Trees serve as the foundation, supporting hundreds of caterpillar species that feed baby birds.
Every decision about fall cleanup affects vital creatures most of us never see. When you leave those leaves, you're protecting the pill bugs that decompose organic matter, returning nutrients to the soil. You're sheltering the spiders that will control pest populations next summer. You're preserving the native bees -- over 70% of which nest in the ground and depend on leaf litter for insulation.
These seemingly insignificant creatures provide essential ecosystem services, including pollination, nutrient cycling and natural pest control. When insect populations decline, the effects cascade through entire food webs. In Europe, over the past 30 years, declines in bird populations have been attributed to a scarcity of insects.
This weekend, commit to one act of strategic laziness. Rake those leaves into your garden beds. Leave those flower stalks standing. Mark off a small corner of your yard as a "wild zone" where natural processes can unfold.
The insects overwintering in your yard may be out of sight, but their fate shouldn't be out of mind. These creatures are nature's unsung heroes, and your yard can be their sanctuary. Next spring, when you see that first butterfly, hear that first robin or watch native bees visiting your flowers, you'll know that your decision to leave the leaves made it possible.