It’s antithetical to the established ideal of beautifully kept gardens to let fallen leaves pile up on lawns every autumn, where they’ll slowly decay into unsightly blackened blankets across suburban yards. At least, this is what the common mindset has been for several centuries. But what would happen if people left fallen leaves on their lawns instead of raking them up? What are the benefits of doing so, other than having pristine, manicured spaces? Let’s look at the reasons why leaving your leaves is one of the best things you can do to help both your local ecosystem, and the world as a whole.
Why are Fallen Leaves Viewed with Such Contempt?
Due to the enormous labor and resources required to keep them looking verdant, lawns have been cultivated as status symbols of the wealthy since the 17th century. Over time, lawns were democratized so that everyone with a home considered a lawn to be a necessary part of the “good life”.
In the U.S. alone, lawns comprise over 44 million acres of land, which is close to the total number of acres dedicated to its national parks. While many garden trends have come and gone, homeowners continue to cling to the luxury a soft velvety lawn promises, despite the concrete evidence that lawns are drastically reducing biodiversity in our ecosystems.
That said, millions of homeowners aren’t ready to dig up their lawns in favor of more natural landscaping. That’s okay: there’s one thing they can commit to doing that will make them eco-heroes: stop raking their lawns.
There are three main ecological benefits in not raking leaves off your lawn:
- They decompose into rich fertilizer for both plants and microorganisms
- They provide winter cover for many pollinators and vital animal species
- They improve overall soil structure
Free Fertilizer
The next great value that leaves on your lawn provides is free, safe fertilizer. Decomposing fallen leaves break down through the work of leaf-eating insects. Millipedes, woodlice, and earthworms leave droppings behind, which are rich in nutrients your lawn needs to thrive.
Homeowners in the U.S. use over 90 million pounds of synthetic fertilizers on their lawns every year. One of the most serious ecological problems this creates is runoff into rivers and lakes causing eutrophication. Basically, excessive nutrients cause a dense overgrowth of plants in waterways. This in turn uses up oxygen, causing the death of animal life.
Safeguarding the balance of plant and animal life in our waterways is vital for all living organisms. Furthermore, synthetic fertilizers are unnecessarily strong and dependence on them is expensive. In contrast, autumn leaves are like dollar bills dropping from the sky to the precise spot where they’re needed.
Animal Species We Depend Upon Need Leaf Litter to Survive
Human food security leans heavily on pollinators to produce fruits and vegetables in large crops. In theory, farmers could pollinate all their plants by hand, but it would be so labor intensive that nobody would be able to afford food grown that way. Ecologists and environmentalists have been reporting steep declines in pollinator populations for years now. While awareness has encouraged gardeners to plant more nectar-rich flowers, that only sustains them though part of their life cycle. What they need as much as nectar is for everyone to stop raking up their leaf litter in fall. This is because it provides a warm dry place for overwintering pollinators. Butterflies, bumblebees, Eastern Red bats, moths (including the breathtaking Luna moth) and beetles all benefit from this habitat.
It’s important to think beyond just the pollinators when we’re talking about healthy ecosystems. For example, there are many other invertebrates and small animals that we need for healthy ecosystems. They also offer great benefits to the health of people’s homes and gardens. For example, snakes not only overwinter in cozy piles of leaf litter, they also hunt for food in them. This means eating animals such as rodents, which carry zoonotic diseases. That’s a huge benefit for humans.
Frogs, turtles, salamanders, and hedgehogs (in Europe) also overwinter in leaf litter. They eat slugs, mosquitoes, flies and other invertebrates that homeowners typically think of as pests. Another heavy hitter in the ecosystem are spiders who also help keep many different “pests” in check where humans live. Fewer pests means less need for pesticides in lawn and yard care which saves homeowners money and time. It also helps keep our waterways safer for everyone.
Related Article: Water scarcity – A looming global crisis
Why Improved Soil Structure is So Important
Every year, flooding is becoming more and more common in cities across North America, in places where it used to be a rare occurrence. Climate change is certainly a major contributing factor. Another factor is the urbanization of land — covering acreage in non-permeable surfaces like asphalt and concrete. There’s a third serious factor that contributes to increasing problems with flooding: vast areas of compacted, poor soils.
The more factory farms and home gardeners depend on synthetic fertilizers (as opposed to natural composted plant material), the poorer the soil structure on their property becomes. If the only thing you feed a lawn is chemical fertilizer, you’re not replacing the organic matter that’s in a constant state of being consumed by billions of organisms living in it. The soil compacts over time, reducing available oxygen, killing everything that lives in it.
Another important factor is that compaction greatly reduces soil’s ability to absorb water. By letting leaves decompose where they drop, you allow that soil structure to continually be refurbished with fresh organic matter. You can, of course, go buy some ready-made compost, but it gets more expensive every year. The leaves that fall from the trees around your house continue to be completely free.
Perceived Downsides to Not Raking Away Fallen Leaves
Aside from the messy appearance of not raking the lawn, the biggest reluctance most lawn owners have to leaving fallen leaves decompose where they fall is a fear that doing so will destroy their grass. It’s true that if you leave a thick layer of leaves on your lawn all winter, your lawn may develop some bare spots. If you’re eager to get all the benefits of leaving your leaves unraked, but the trees in your yard drop an excessive amount of them, there are a couple of things you can do to mitigate this factor.
The first is that you can rake some of them into your flower beds and around the base of your trees. This will leave only a modest amount on the lawn itself. The second thing you can do is to use a mulching lawn mower without the bag. This scatters the mulched leaves around as you mow. Smaller leaf litter won’t provide adequate shelter for the larger animals and invertebrates you want to invite into your garden in abundance, but it will still be good for the smaller ones. Furthermore, it will fertilize your lawn and build better soil structure, allowing for better water absorption and retention.
It’s Time to Change Our Perspectives on Traditional Lawns
Lawns have been part of our culture for so long that it’s hard for most people to imagine a future without them. It’s become so deeply connected to people’s pleasurable sense of childhood and family — leisurely picnics, cool places to rest on hot days, a soft place to play games — that it’s almost become part of their DNA. While many homeowners are embracing more natural and ecologically-minded garden styles, millions of people are still holding fast to their traditional patch of grass. The way to bring the traditional lawn into a promising biodynamic future is to simply leave the leaves where they fall.
Photos by Patti Black, Adam Bašić, and Shirin Saleki, via Unsplash Creative Commons.