Experts give you permission to stop raking your leaves this fall. this is the reason
But some view fall foliage as a mess to be overcome rather than a source of crunchy joy.
Read more: The science behind the scent of fall
The hallmark of fall lawn care — trying to get rid of every leaf that falls on one’s property — comes at an environmental cost, experts say.
“Foliage is often thrown away, treated as litter,” said Matthew Shepherd, director of outreach and education at the Xerces Society for Invertebrate Conservation. By collecting and packaging them all, “we are unwittingly impoverishing our landscapes.”
Lawns make up millions of acres of land in the United States, and Americans use many resources to maintain them. But there are plenty of ways to put the abundance of leaves to good use if homeowners choose to work with nature rather than against it, advocates say.
Animation by Megan McGraw/PBS NewsHour
Fallen leaves provide habitat for animals
The thick layer of leaves may not look like much, especially when the color turns pale brown. But it’s probably teeming with wildlife.
As temperatures drop, fallen leaves and the soil beneath them provide a vital habitat for all kinds of creatures, including salamanders, frogs and rodents. The shepherd noted that this shelter is particularly important for the smallest animals, especially insects and other invertebrates. This list includes enveloping butterflies and bumblebee queens, as well as those that may be less striking to humans.
Data show that one square meter of leaf litter can harbor 40,000 to 50,000 small arthropods that are easily overlooked but important to ecosystems. Throwing leaves away eliminates an important source of protection for these and other creatures in the colder months.
“If we take the roof off our house, we’re going to get very cold in the winter,” Shepherd added. “If we leave the leaves down, we’re leaving the roof off all those bugs.”
The leaf litter is also a destination for non-migratory birds such as cardinals, who hop around and feed on insects sheltering below.
In a shepherd’s garden, he leaves the flower stalks and seed heads standing, providing additional ground cover and food options for wildlife. It benefits from bird watching during the fall and winter, and is an entertaining show from the warm interior.
“There’s a lot of life you bring into your garden simply by being untidy,” he said.
Fallen leaves are rich in nutrients
Dead leaves play a major role in infusing the soil with new nutrients. Invertebrates that come to eat the leaves begin the process of breaking them down before microbes help finish the job.
When trees absorb carbon dioxide for photosynthesis, it is stored in their bark, trunks and roots, as well as their leaves, said Teresa Crimmins, director of the National Phenology Network in the United States of America.
Leaves that fall from trees in autumn release some carbon dioxide into the atmosphere as they decompose, but the carbon is also taken up by organisms that feed on the leaves. This includes earthworms, whose feces are “essentially soil,” she noted.
In addition to worm food, leaves are a great natural mulch on flower beds until it’s time to prepare your garden for the next growing season. They’re really important for the soil because they add “organic matter — which can help retain moisture — they add nitrogen back into the soil, and they can also play an important role in suppressing weeds,” Crimmins said.
Dumping or burning yard waste contributes to pollution
Getting rid of fallen leaves isn’t just harmful to your local insect populations — it can also contribute to greenhouse gas emissions that lead to global warming.
Yard waste, which includes discarded papers, makes up about 12 percent of all municipal solid waste in the United States. The majority of this waste is composted, which is good — but roughly a third of it ends up in landfills, Gregory Killian, director of the Center for Sustainable Systems at the University of Michigan, tells PBS NewsHour via email.
He explained that when these leaves are left to rot in landfills, they release methane gas due to anaerobic bacteria that thrive in that oxygen-poor environment.
Burning leaf piles is another popular solution for getting rid of leaves, but it comes with its own risks. First, burning any materials poses a fire hazard, which is why people in dry areas should be especially careful when doing so. Kyulian noted that burning leaves also releases toxic particles and chemicals that can be particularly harmful to those with respiratory problems.
“Burning anything creates low-level pollution,” said Beth Clawson, an extension professor at Michigan State University.
When fires burn close to the ground, that smoke stays close instead of mostly being transported into the atmosphere, she added. For this reason, smoke stacks in factories need to be fairly tall, Clawson said, so that there is less chance of their emissions reaching people directly.
Fall garden management tips
If you’re not completely convinced to go with the cards, don’t feel too guilty. No one expects homeowners to make a binary choice between planting a tidier yard or a completely wild one, Shepherd said.
Instead, proponents say, determining where leaves can be left alone and where you want to clean them can help you reach a reasonable compromise between home maintenance and grounds management.
“It’s about getting to that balance between which areas of your garden do you want your kids to play in, which do you want to sit in, etc.? And which areas of your garden can be allowed to be more natural?” The shepherd added.
Here are some additional quick tips from experts:
- Check if your community offers composting. If not, consider creating your own pile on your property.
- Start a fire or use an electric leaf blower, if you can. Both of these options are better for the environment than gas-powered leaf blowers, Keulian said.
- You can use a leaf shredder or shred them with a lawnmower, but… Shepherd noted that although these leaves make a good mulch or natural fertilizer, the shredding process will unfortunately be a mass casualty event for all the insects that have settled in those leaves.
- Help researchers track fall changes. The National Nature’s Notebook invites people to report their observations of animals and plants — including leaf drops — throughout the year using a tool called Nature’s Notebook to help policymakers make decisions.