Fall Yard Habits Can Save Pollinators, Experts Say
Simple changes to autumn yard maintenance can provide crucial winter habitat and resources for bees, butterflies, and other beneficial insects.
Many homeowners consider fallen leaves, standing dead stems, and even hollow branches as yard waste to be cleared away each fall. However, ecologists and entomologists emphasize that these elements are vital for the survival of pollinators and other beneficial insects throughout the winter.
Katie Costanzo, an ecologist and entomologist at Canisius University, discovered this firsthand when her students analyzed bags of leaves collected from curbsides in Buffalo. The leaves were teeming with insects in various life stages, including bees, wasps, lacewings, hoverflies, and beetles, all seeking shelter or sustenance.
"This is part of the ecology of our system," Costanzo stated, advocating for a shift in perspective from viewing these natural materials as trash to recognizing them as potential habitat or resources. Mary Phillips, head of native plant habitat strategy at the National Wildlife Federation, echoed this sentiment, explaining that much of what appears dormant in winter is actively serving as food, shelter, or a nursery for various creatures.
Queen bumblebees may be overwintering just beneath the soil's surface, while native bees and ladybugs can find refuge in hollow stems. Spent flower heads offer shelter for beetles, flies, and weevils, and their seeds provide food for birds. These overlooked aspects of a yard are crucial for maintaining biodiversity.
Rethinking Fall Cleanup
Ecological landscape designer Kim Eierman, author of The Pollinator Victory Garden, encourages homeowners to view even small yards as ecosystems that require conscious management. This perspective often leads to reconsidering familiar features like closely cropped lawns, which she describes as "green deserts."
Experts recommend several fall yard habits to support pollinators:
Designate a Cleanup-Free Zone
Divide your yard into zones, maintaining high-traffic areas while designating a quieter section where leaves, stems, and branches can remain undisturbed. This practice acknowledges the need for functional spaces while also preserving vital habitat. Eierman suggests using signs to inform neighbors about this approach to gardening.
Rake Leaves into Garden Beds
Instead of bagging leaves, rake them into garden beds or beneath trees to a depth of 3 to 5 inches. This leaf litter insulates hibernating insects, shelters invertebrates, and enriches the soil as it decomposes. Leaves should be moved from turf and walkways where they can create hazards. Excess leaves can be piled in a corner to form leaf mold.
Shredding leaves with a mower is an option, but should be done early in the season before insects have settled. Diseased plant material and invasive plants may require disposal according to local guidelines. In wildfire-prone areas, clearing leaves and debris near structures is essential for defensible space.
Leave Stems and Seed Heads Standing
Allowing dead stems and seed heads to remain standing provides nesting sites for insects and food sources for birds. Hollow or pithy stems can shelter overwintering insects, while seed heads offer sustenance. Standing plants can be supported with twine to prevent toppling. If stems must be trimmed, leave at least a foot standing, varying heights to accommodate different insect species.
Diseased plants should be removed, but otherwise, standing dead vegetation is beneficial. For homeowners concerned about aesthetics, trimming unruly stems or gathering them can offer a compromise.
Expose Some Bare Ground
Many native bees nest in the ground, and thick layers of mulch can impede their access. Designate small areas where mulch is pulled back, leaving a patch of exposed, undisturbed soil. This provides crucial nesting habitat for ground-nesting bees.
Preserve Logs and Branches
Fallen logs, sticks, and brush piles offer structure and shelter for insects and other wildlife, and birds often forage in these areas. These materials can be moved to less conspicuous locations like behind shrubs. Starting with a small log or a restrained brush pile can provide significant habitat.
Plant Native Species
Fall is an ideal time to plant native species, as cooler temperatures and increased moisture benefit new plants. Choosing plants native to the region and suited to the site's conditions supports local ecosystems. Oak trees, for example, are known to support hundreds of species of caterpillars. Even smaller plants like shrubs, grasses, and perennials contribute significantly.
When selecting plants, ensure they are not sterile cultivars that fail to produce pollen, nectar, or seeds. Fall is also a good time to collect and sow native seeds, allowing winter conditions to prepare them for spring germination.
Avoid Unnecessary Pesticides and Herbicides
Pesticides and herbicides should be used only when a specific problem arises, not as routine fall maintenance. Broad-spectrum insecticides kill beneficial insects along with pests. Herbicides can eliminate plants like clover and dandelions that provide food for pollinators. Targeted treatments are recommended only when necessary, and only on the affected area.
Recognizing that insect damage on leaves can be a sign of a healthy ecosystem, rather than a problem to be solved, is also important. A few holes in a leaf typically do not harm a healthy plant and indicate that the plant is serving its ecological purpose.
Implementing these practices can lead to significant benefits, not only for wildlife but also for human well-being. A National Wildlife Federation survey found that most wildlife gardeners reported improved mental and physical health, enjoying the presence of wildlife and the satisfaction of contributing to environmental health. The positive effects can often be observed within a single season.