“Leaving the leaves” is how we can help pollinators get ready for cold weather.

Last autumn, Jessica Miller took some of her neighbors’ raked-up leaves and spread them out in her yard. She put layers in her garden beds and small piles around her trees and shrubs. In a society that prizes the pristine lawn and tidy garden, leaves are often seen as a messy nuisance. But one person’s trash is another person’s treasure. In Jessica’s yard, leaf piles are not messes but strategically placed patches of habitat that help both wildlife and the health of her yard.  

“Nature doesn’t make garbage,” says Jessica, an environmental entomologist who shares about the wonder of insects through her organization Dragons Wynd. “The less you’re manipulating, the more that nature is going to do what it would normally do.” Fallen leaves are a resource. Over time, they decompose, returning nutrients that trees and plants need the following year. 

Before leaves break down, they provide essential shelter for insects. Jessica explains that there are a lot of insects that use leaves to overwinter. By October, insects beneficial to our ecosystems may be bedding down, some making cocoons in leaves on the ground. That includes native bees, butterflies, moths, beetles—and even amphibians like frogs and salamanders. “Leaves create air pockets and insulated spaces,” says Jessica. “They become like little sleeping bags.”

Other Plant Matter Provides Shelter, Too

It’s not just leaves that insects rely on for shelter. Bumble bees make nests in brush piles or underground cavities. Hollow stems and dead wood provide habitat for the larvae of stem-nesting bees. Jessica likes to create more “housing” for these bees by breaking stems off plants like goldenrod after they go to seed. Breaking the stems at variable heights also gives falling leaves more spaces to settle.

One reason Jessica gets excited about “leaving the leaves” in the fall is because it’s an opportunity to make a difference for pollinators by doing less work, not more. Whether you’re eager to toss aside the rake or still hesitant about letting things stay a little messy, here are some key tips to keep in mind:

• There are some places we do need to keep clear of leaves. Leaves are rich in nutrients, which is great if they enter the soil and directly feed your trees and plants (goodbye, store-bought fertilizer!). But leaves that fall onto sidewalks and streets can wash into storm drains that empty directly into our lakes, rivers, and streams, triggering algal blooms that put water quality and the health of aquatic ecosystems at risk. So take the time to rake leaves from hard surfaces and keep them out of storm drains.  
• Leaves don’t always break down easily when left on turfgrass. To help speed up the decomposition process (and prevent exposing your lawn to mold or disease), mulch your leaves by running them over with a lawn mower. This breaks them into smaller pieces.
• Do you want a neater look? Rake your leaves, but instead of putting them in a bag, move them to less-trafficked areas of your yard. Garden beds are a great option because spring-emerging plants will benefit from the breakdown of nutrients that comes from those leaves. You can use wire or a similar material to create self-contained areas for your leaves to compost passively. 

When planning for your fall yard care, Jessica suggests stepping back and considering your yard’s ecosystem. “When you leave out leaf litter, seeds take hold more easily. More moisture can be held in for plants,” she says. And of course, when plants are thriving, the creatures that rely on them can also thrive.

This includes insects that don’t spend their winters here, like the migratory monarch butterfly. 

“We can ‘caretake’ those plants that monarchs will need the next season,” says Jessica. By collecting and planting native milkweed seeds in the fall, for example, returning monarchs will have more food and habitat for their eggs. 

What excites Jessica most about this season is learning about the range of different things insects do in winter. “A lot of our local butterflies and moths overwinter as cocoons or pupae, for example,” says Jessica. “But the mourning cloak butterfly overwinters as an adult.” How do different pollinators settle in for the winter? What kind of materials do they need for shelter? Asking questions like these can guide how you prepare your yard for the winter. 

Just remember that simply leaving the leaves can go a long way towards helping our pollinators thrive!

— Megan Reich, Metro Blooms Communications and Program Manager

Additional Resources: 

• Learn more about Jessica Miller’s work through Dragonswynd on her website.
• The Xerces Society’s “Leave the Leaves” campaign provides a primer of invertebrates and the types of winter habitats they rely on.
• The Mississippi Watershed Management Organization has a blog post filled with water and pollinator-friendly fall yard care tips. 
• The University of Minnesota Bee Lab has an online guide for creating bee nesting habitat.
• University of Minnesota Extension has a  helpful video on fall cleanup for pollinators.