EarthTalk – How many sites join Xerces’ “Leave the Leaves”?

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Dear EarthTalk:
What is the Xerces Society’s “Leave the Leaves” campaign all about and how many sites participate?
Randy J., Newark, NJ

The Xerces Society’s “Leave the Leaves” campaign asks homeowners, grounds crews, municipalities and campuses to rethink the annual ritual of removing every fallen leaf and dead plant stem. What looks like untidy yard debris can be essential winter habitat for insects and other invertebrates.

Many butterflies, moths and bees overwinter close to where they spent the growing season. Fritillary and woolly bear caterpillars shelter in leaf litter; luna moths and swallowtails disguise cocoons or chrysalises as dead leaves; and mated bumble bee queens burrow only an inch or two into soil, where leaves provide insulation. About 30 percent of native bees nest in tunnels and may use hollow stems, dead wood or brush piles.

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The advice is not to abandon every lawn. Xerces recommends leaving leaves where practical or raking them intact into garden beds, beneath trees or into designated piles. Leaves can suppress weeds, retain moisture and return nutrients as they decompose. The group discourages shredding because mowers can destroy insects, eggs and cocoons inside the leaves, and recommends delaying spring cleanup until overwintering wildlife has emerged.

“It not only needs leaves, it looks like a leaf,” says Xerces pollinator ecologist Ray Moranz of the goatweed leafwing butterfly, whose camouflage depends on leaf litter.

How many sites participate is harder to answer than the slogan suggests. Leave the Leaves is an open public-education effort promoted through social media, yard signs and downloadable materials; Xerces publishes no registration total for every household, park or institution following it. Its Bee City USA and Bee Campus USA network is the campaign’s most identifiable distribution system. The latest completed public tally lists 426 affiliates at the end of 2024—224 cities and 202 campuses—but that figure represents affiliates able to use the campaign kit, not proof that every one ran a Leave the Leaves activity. The 2025 affiliate report is scheduled for September 2026.

Real-world adopters demonstrate the idea’s flexibility. UC Davis encouraged residents to preserve leaf litter through its Bee Campus USA affiliation. Greensboro, North Carolina, launched a pledge program offering Leave the Leaves yard signs to residents and businesses. Raleigh advises residents to rake leaves into beds, create a decomposition pile or leave them where they fall, while keeping heavy layers off turf and storm drains.

Readers can participate by preserving whole leaves in low-traffic garden areas, retaining some hollow stems and brush, keeping streets and drains clear, and explaining the intentionally wildlife-friendly landscape to neighbors.