Every fall, a significant number of dutiful homeowners get out their rakes, gather leaves into piles and pack them into giant bags to be hauled off to landfills. This yard waste may seem like an innocuous addition to the waste that’s added to U.S. landfills each year, but it quickly adds up.
Yard trimmings, which include grass, leaves, and tree and brush trimmings, accounted for 34.7 million tons of municipal solid waste (MSW) in 2015, which is 13.3% of total MSW.1 Some of these yard trimmings ended up being composted via state and municipal programs, but 10.8 million tons of yard trimmings still ended up in landfills that year, comprising 7.8% of MSW added to landfills.2
Not only do leaves add to the high volume of waste already being sent to landfills, but when they break down, they release damaging methane gas into the environment. “The worst thing you can do is put (leaves) in bags and send them to landfills,” David Mizejewski, a naturalist at the National Wildlife Federation (NWF), told USA Today.3
Leaves Are a Perfect Fertilizer
Fallen leaves act as a natural mulch that will break down and fertilize the soil while helping to keep weeds in check. While it’s true that a thick layer of leaves can smother your lawn, this is easily remedied by running over them with your lawn mower. If there are a lot of leaves, it may take several passes with your mower to get them to a small enough size, such that the shredded bits fall between the blades of grass.
Because this acts as a natural form of fertilizer, you won’t need to add more in the fall, which can reduce the amount of chemical fertilizers added to lawns. Further, leaves mulched into your lawn will help to reduce fertilizer runoff, which has become a problem for waterways, leading to algal blooms that are harming wildlife.4
If there is still a thick layer even after mulching them via your lawnmower, rake up the remainder and spread it as mulch under trees and shrubs and in flower beds and your vegetable garden. While you can also use whole leaves for this purpose, the shredded texture allows the leaves to break down faster while making them less likely to blow away. It’s unnecessary to throw away this valuable and free fertilizer.
Sharon Yiesla, plant knowledge specialist at the Morton Arboretum in Lisle, Illinois, told the Chicago Tribune, “Most people rake leaves because they assume that’s what you’re supposed to do, or because they think leaves are untidy … They don’t realize how valuable the leaves are to plants or how useful they can be in the garden.”5
For leaves that fall under trees or shrubs, simply leave them be, as would occur in a forest. By spring, the leaves will be mostly broken down, making your soil easier for roots to penetrate and better draining.6
If you have a large pile of leaves, you can also simply let it be for a year or two, after which time it will break down into leaf mold, a soil amendment that improves soil structure and water retention. It’s so valuable the Morton Arboretum uses it as mulch in its ornamental plant beds.7 Mizejewski added:8
“Fallen leaves offer a double benefit. Leaves form a natural mulch that helps suppress weeds and fertilizes the soil as it breaks down. Why spend money on mulch and fertilizer when you can make your own?”
Leaf Litter Is Important Wildlife Habitat
Sending leaves to a landfill creates unnecessary waste and removes what could be a nourishing, free fertilizer from your yard. At the same time, by removing fallen leaves, you’re taking away leaf litter that many creatures rely on for their very survival.
Turtles, toads, birds and mammals such as bats use leaf litter for food, shelter and nesting material. Insects, including moth and butterfly caterpillars, also rely on leaf litter to overwinter. According to Mizejewski in an NWF blog:9
“The leaf layer is its own mini-ecosystem! Many wildlife species live in the leaf layer as their primary habitat — including salamanders, chipmunks, wood frogs, box turtles, toads, shrews, earthworms, millipedes and many insects species.
Many butterfly and moth species overwinter in leaf litter such as luna moths, great spangled fritillaries, woolly bear caterpillars (which become Isabella tiger moths) and red-banded hairstreaks.
Some overwinter as eggs, some as pupae and some as adults. If you rake up and throw away all of your leaves this fall, you’ll be getting rid of these beautiful and beneficial insects, many of which are pollinators.”
It was recently revealed that 2.9 billion Canadian and U.S. birds have been lost over the last 48 years,10 including not only rare species but also common birds at backyard feeders, such as sparrows, warblers, finches and blackbirds.11 Leaving leaf litter in your yard is one way to help protect these and other declining wildlife species. “This is wildlife conservation on the scale of your lawn,” Mizejewski said.12
Avoid Leaf Blowers
If you do need to move around the leaves in your backyard, use a rake — not a leaf blower, which is a source of noise pollution that could even damage your hearing. According to Nancy Napolitano, interim director of audiology at St. Luke’s University Health Network, more people are arriving with noise-induced hearing loss than in years past, many of them in their 50s and younger.13
It is believed hearing damage is triggered at 85 dB of exposure for approximately eight hours. To compare, traffic noise inside your car measures 80 dB, while a leaf blower can measure between 90 and 115 dBs depending on the device. Exposure to 90 dBs of noise for two hours can trigger hearing damage.
While wearing ear protection can buffer some of this risk, wearing a leaf blower strapped to your back may also increase your risk of exposure to electromagnetic fields (EMF). Many are also gas-powered, and some U.S. cities have banned them due to concerns over noise and air pollution.14
Leaves Make a Valuable Brown Addition to Compost
If you have a compost pile or bin, fallen leaves are a welcome addition and act as “brown material” that should form the bulk of the compost. The key to creating compost without unpleasant odors or attracting rodents lies in its makeup. It’s not an exact science but should include a mix of browns and greens, such as:15
|Browns (2 to 3 parts)||Greens (1 part)|
Shredded newspaper and other paper
Fruit and vegetable scraps
Breads and grains
Food-soiled paper (but not coated paper)
Coffee grounds and filters, tea bags
Branches and twigs
As an added benefit, when you create a compost heap in your yard you can add not only fallen leaves but also kitchen scraps. Food waste is the second largest component of waste sent to U.S. landfills, making up 18% of the waste stream, according to the U.S. EPA.16 By composting, you’re not only keeping your share of food waste out of landfills, but you’re also helping to pull carbon dioxide out of the atmosphere and sequester it in the soil.
Compost regenerates the soil and in so doing supports the future of our food supply, human health and the planet as a whole, while providing a free and simple way for you to repurpose fallen leaves in your yard.
Benefits of Johnson-Su Bioreactor Compost
The video above shows the Johnson-Su Composting Bioreactor. David Johnson, a molecular biologist and research scientist at the University of New Mexico, believes one of the most critical things in a plant’s life is its relationship with mycorrhizal fungi. This is why tillage is so detrimental, as it destroys the mycorrhizal fungi and disrupts or inhibits this symbiotic relationship between plants and soil biology.
Synthetic chemicals also have a very destructive effect as they create massive pH changes in the soil that kill microbial life. As a result of industrial agriculture and other human activities, one-third of the soil on Earth is severely degraded17 and lacking in the beneficial microorganisms it needs to thrive.
Adding compost is one effective strategy for reintroducing such microorganism to the soil, and Johnson has developed a no-turn composting system that allows fungal communities to flourish, helping to restore biological function to soil on both small and large farms.
Johnson is conducting a range of soil-biology experiments that have shown immense benefits from the application of biologically enhanced compost, which has a clay-like consistency and can be applied as an extract, slurry to coat seeds or as a direct soil amendment.18
The Johnson-Su Composting Bioreactor, created by Johnson and his wife, Hui-Chun Su Johnson, is unique in that, unlike traditional composting methods, it requires no turning or manual labor.
It also produces no odors, reduces water usage and composting labor and can be produced using materials that costs less than $35. “This simple composting method produces a biologically enhanced compost by creating an environment where beneficial soil microorganisms and thrive and multiply,” Regeneration International reported.19
“When this biologically alive compost is applied to the soil the microorganisms inoculate the soil and work in harmony with growing plants to improve soil health and increase the amount of carbon drawn out of the atmosphere and into the soil.” They explained some of the top benefits of Johnson-Su bioreactor compost, which include:20
Increases soil carbon sequestration
Increases crop yield
Increases soil nutrient availability
Increases soil water-retention capacity
Produces biologically diverse compost
Produces nutrient-rich compost
Results in a low-salinity compost
Improves seed germination and growth rates
Put Fallen Leaves to Work in Your Yard
Instead of spending hours raking leaves in your yard, let the fallen leaves work the way nature intended, acting as insulation, a source of nutrients and habitat for critters. Adding them to your compost bin is an ideal solution, one that will reward you with a rich soil amendment that you can apply to your gardens come spring.
However, mulching the leaves by running them over with your lawnmower can also add innumerable benefits to your lawn. When shredded into small pieces and allowed to return into the lawn canopy, different leaf types offer different benefits. For instance, maple leaves reduce weed seed germination while honey locust leaves are known for adding nitrogen to lawns.21
One study even noted, “mulched leaves, regardless of maple species, reduced dandelion counts by up to 84% after a single application.”22 So no matter which method you choose — mulching, composting or creating leaf mold — let the fallen leaves in your yard work for you, not against you.
“Leaves cover up root systems, preserve soil moisture, suppress weeds and other plants. They also slowly break down and … return (essential) nutrients to plants,” Mizejewski told USA Today. “It’s a perfect system. Nothing is wasted in nature.”23