When you clean up leaves, you clean out habitat for overwintering bees, butterflies, and many other critters. On the flipside, leaving leaves in place will give them the shelter they need to make it through the winter.
Leave the Leaves
Even after they fall to the ground, leaves serve a purpose. For one, leaves that decompose at the feet of trees return nutrients to the soil that will support the trees’ spring growth. On the other hand, cleaning up and sending leaves away removes these nutrients from our property.
Fallen leaves help animals too. Many insects hibernate through the winter in leaf litter and other dead plant material like hollow stems. In the fall and winter, larvae and cocoons of many species of butterflies and moth are nestled in the leaves beneath your feet. The American bumble bee also depends on leaf litter. The queen bees burrow an inch or two into the soil and need a layer of leaves to protect them from the bitter cold.
In turn, overwintering bugs are an essential winter food source for birds. They will forage through leaf litter for insects and larvae. Birds also eat seeds from plants that are left standing through the winter.
Simply put, leave leaves in place to help wildlife survive the winter. This makes your fall chores a bit easier and goes a long way to protect animals that spend the winter here. When it warms up in the springtime, the critters will emerge from their winter homes in the leaves and soil. Typically, we recommend you wait until it warms up to a steady 50 degrees to clean out dead plant material from your garden beds. This gives insects have ample time to wake up and move out. Leaves can be left to decompose into the soil.
Animals That Depend on Fallen Leaves
A whole host of species spend the winter tucked beneath leaves or a few inches into the earth, including:
This beautiful moth spends the winter as a cocoon camouflaged among the leaves.
American Bumble Bee
Queen bumble bees bury themselves an inch or two into the earth to survive the winter. Fallen leaves form a layer of insulation over them.
Woolly Bear Caterpillar
The caterpillars that are said to predict the harshness of the winter by the length of their black bands often overwinter in leaf litter.
Birds, chipmunks, amphibians, and turtles also indirectly depend on fallen leaves since overwintering insects are an important part of their diets this time of year.
If You Can’t Leave Them Completely…
Sometimes we can’t resist the call of a tidy yard. Or more realistically, maybe your Homeowners Association has strict rules. However, there might be a way you can compromise and still use some leaves to benefit the environment.
For example, if you can’t leave them totally in place, there’s likely a small part of your yard where you can keep leaves. Garden beds and around landscaping are great places to rake leaves into so wildlife will be able to find winter homes.
Another option is to use leaves as a natural, slow-release fertilizer. Mulch them with a mower and leave the shredded leaves to fertilize your lawn, or compost the mulched leaves. While mulched leaves are less helpful for wildlife, they will build healthy soil in your lawn and around landscaping.
In Conclusion, Leaves Are Great for Animals and Soil Health
If you can, leave the leaves this fall to help insects like bees and butterflies—and the birds that eat them—survive Illinois’s harsh winter. If that’s not an option, pick a section of your yard or garden to hold leaves. Or, mulch leaves into your lawn or add them to the compost pile. This way you are still keeping leaves on your property where they will return nutrients to the soil instead of sending them away.
Are you leaving the leaves at home?
If you are leaving leaves for wildlife and doing other environmentally-friendly practices at home, like gardening with native plants and conserving water, you are likely eligible for certification through the Conservation@Home program!