Humane Gardener

Fallen leaves provide foundational year-round habitat for countless animals (in ways that might surprise you!)

Green frog hugged by tulip poplar leaves

There’s not much sadder to me than walking into a home that’s festooned with garlands of plastic leaves inside but surrounded on the outside by over-mown, overblown lawn. Faux-nature decorations—including stacked straw bales, pumpkins that no one will ever eat, and polyester leaves stamped out in a factory—are on full display at the entrance to my mom’s apartment building this week, even while outdoor crews wield anti-nature weaponry to vacuum all the real leaves away.

In an age of nearly ubiquitous destruction, this particular sign of a culture of misplaced priorities punches me in the gut more than most other harmful landscaping practices. I don’t begrudge people for taking joy in the colors and shapes of leaves and the memories they invoke: childhood hay rides, steaming cups of hot chocolate, walks home from school in the chilled autumn air, and, if your parents were accommodating, a chance to jump into the newly raked piles.

Fallen leaves around silver maple — What could be prettier than the real thing? For wildlife, the fallen leaves in our front habitat aren’t just decorative; they’re home.

But if the sight of those fake leaves invokes nostalgia in others for what once was (or a longing for what they wish had been), then the sight of a leafless outdoors makes my heart ache for the present—for the animals who can no longer find the fallen leaves they need for food, nesting, cover, camouflage, and winter hibernation.

The last time I dedicated a whole article to life in the decay, “These Animals Are Made Possible by Fallen Leaves,” someone created a meme based on the concept and shared it widely on social media. But unfortunately the creators of the graphic added something I don’t support—a validation of the concept of mowing over leaves, or “mulch-mowing.” If your goal is to grow lawn, then shredding leaves while you mow can help return nutrients to the soil and keep your grass blades healthy. Otherwise, mulch-mowing is just one more way to destroy a critical habitat element that’s already all too scarce. It won’t come close to providing the warmth, food, and protection that intact fallen leaves offer year-round—in all these ways and more:

Fallen leaves are underwater blankets

If this bullfrog and green frog don’t try to eat each other first, they can overwinter under a cozy blanket of fallen leaves at the bottom of the pond.

Our culture’s obsession with vacuuming up leaves from the landscape unfortunately extends to waterscapes too. But removing leaves, twigs and branches from a pond greatly depletes the life it can support. Decaying leaves provide habitat for invertebrates in the water, who in turn feed adult frogs, salamanders, birds and other animals. Many organisms, including some aquatic insects, shred and graze the organic matter and help to break it down. When temperatures drop, bull frogs and green frogs burrow into the decomposing vegetation at the bottom of the pond to ride out the winter.

Fallen leaves are nesting material

In the canopy, squirrels and birds insulate their nests with leaves, and bumblebees sometimes reuse those well-constructed homes to raise their own young. On the ground, nature’s best rodent patrols, black rat snakes, often lay eggs and take cover among fallen leaves too. In winter, chipmunks and opossums stay warm in burrows lined with leaves, and come spring, fallen leaves make the perfect spot for mama rabbits to raise their babies.

Baby rabbits are cozy and hidden among the fallen leaves.

Fallen leaves are camouflage

Squirrel by pond — Squirrels match leaves and are often detectable only by their constant motion.

Have you ever noticed how difficult it can be to locate animals in the fallen leaves? Squirrels, deer, wood thrushes, toads, turtles and innumerable other creatures blend in to the environments where they thrive. None of them evolved to live in giant swaths of turfgrass. Many are darker above and lighter underneath, a type of coloration known as “countershading,” which can distort shadows and make it harder to discern shapes. When I want to do some serious wildlife-watching, I look no further than down on the ground, toward the abundant leafy layer.

White-throated sparrow foraging in fallen leaves — A wood thrush by our front path has the mottled look of a sun-speckled forest.

Deer lying in fallen leaves — A wood thrush by our front path has the mottled look of a sun-speckled forest.

Fallen leaves are song and motion

Northern flicker in fallen leaves — Northern flickers find ants in leaves.

Eastern towhee in fallen leaves — Northern flickers find ants in leaves.

Wildlife gardeners already know how important the understory is for winter forage. Seed and insect treats are abundant in the ground layers, where some birds send leaves flying throughout the year to find the treasures underneath. Mammals forage there too; in the depths of winter, deer sometimes even make drying leaves a part of their diet.

While indulging their appetites, the animals bring music and bursts of motion to landscapes filled with leaves. White-throated sparrows herald the coming of shorter days here in the mid-Atlantic with their ethereal song. Mixed flocks of cardinals, tufted titmice, chickadees, and nuthatches chitter-chatter away together during the cold season. All of their movements are easier to observe in winter and early spring when dormant plants no longer obscure the view—and there’s nothing quite like watching northern flickers flick and white-throated sparrows kick their way to sustenance.

Fallen leaves are climate control

Insulation and cover are essential to overwintering insects, including butterfly and moth pupae, caterpillars, queen bumblebees and many others. But the rich habitat in the ground layer is also critical year-round. The climate control provided by fallen leaves regulates moisture for fireflies, who are prone to desiccation, and harbors the snails and slugs their larvae eat. Without the help of fallen leaves, our summer nights would lose their sparkle.

Arriving home around 10 p.m. one September, we saw a firefly larva twinkle across the driveway, headed from one leaf-laden garden to another.

Fallen leaves are home sweet home

Box turtle in fallen leaves next to log — This box turtle is much safer in our habitat than in neighboring yards because the leaves help him hide as he forages for slugs, mushrooms and other treats.

If fallen leaves mean so much to animals every day throughout the year, they are just as important to plants. They return nutrients to the soil, keep the ground warmer during the cold seasons, and preserve moisture when temperatures rise. Removing this precious blanket from the already weary earth in order to help a single plant species grow—fescue or bluegrass or zoysia—disrupts the lives of countless beings and often eliminates their ability to survive.

Wood frog in fallen leaves cropped — Wood frogs overwinter under the leaves, but they also spend their summer days searching for invertebrates in the decomposing ground layers.

What can you do instead? First, reevaluate whether you need a lawn at all. Many people rarely venture onto their turf except to mow it every week. If you do happen to use your lawn, you might be surprised by how easy it is to cultivate low-growing native alternatives; letting leaves fall on our old turf encouraged native sedges and ferns to grow and helped us convert our former front lawn into a shady and welcoming woodland.

If you’re wedded to keeping turfgrass, consider reducing its extent. Wherever you can let go of lawn, smother the area with a deep layer of leaves held down by branches and twigs. In spots where you want to preserve turf, gently rake leaves and place them under trees and shrubs and into native planting areas.

And if you’re just starting on this journey, remember that your community is far more diverse than leaf-blowing neighbors would have you believe. Some might look askance at your decision to respect the ground that so many other beings walk, slither and crawl on, but humans are generally not the ones who have to survive out there year-round. Our wild neighbors might not speak our language, but it doesn’t take long for them to show up and let us know—through songs and calls and flurries of activity—just how much they appreciate our efforts.

[Photos and videos by Nancy Lawson]

Pristine Ponds Be Gone!

Wild Waters: Naturalistic backyard ponds welcome frogs and other animals

These Animals Are Made Possible by Fallen Leaves

Grounded and Surrounded: How you can help animals come in for a soft landing

Life After Death: Nurturing life in the decay

Wild by Design