SRU composting advocates ‘break down’ options for fallen leaves


Worker turning leaves

A large-scale composting system on Slippery Rock University’s campus known as “wind rows,” provides a place for autumn leaves to be deposited so they can be broken down into nutrient rich soil.

Nov. 2, 2020

SLIPPERY ROCK, Pa. — Fall is used as an interchangeable term for the season more properly known as autumn because that's when leaves fall from the trees. Fall is synonymous with endings, declines and lapses, and the crumping leaves piling in your backyard are a visual reminder of period without growth. However, there are some people at Slippery Rock University who see fallen leaves as an opportunity for renewal.

"Fall is nature's composting season in many ways," said Sami Laurence, manager of SRU's Macoskey Center for Sustainable Systems Education and Research. "Because things are breaking down in the natural world, this is really the start of a natural process of decomposition, and that leads to nutrient rich soils for plants to grow."

Leaf compost

   Sami Laurence, manager of SRU’s Macoskey Center, holds
compost made from fallen leaves.

Dried leaves are rich in carbon and when combined with other organic materials that are high in nitrogen, such as vegetable scraps or grass clippings, the two decaying materials eventually form fertile soil, a process known as composting.

"When people are composting they're basically mimicking the same type of process that would be happening on the forest floor when leaves fall off trees," said Becky Thomas, associate professor of parks, conservation and recreational therapy. "Leaves naturally break down and they turn into soil, so by composting you're speeding up that process so that you can get to that end point more quickly."

This doesn't mean that homeowners should just "leave" well enough alone and use composting as an excuse to shirk the annual backyard chore of raking the lawn. Laurence and Thomas offer options, beginning with the least desirable.

"Two of the options that are not the best in terms of environmental consciousness are burning the leaves, which a lot of people do, or bagging them up, putting them in the trash and sending them to the landfill," Thomas said. "Burning leaves leads to air pollution and fire hazards and it also releases particles into the air that can cause problems for people with respiratory issues, which is definitely not something we want to be doing when we're already dealing with COVID-19. And once (bagged leaves) get to the landfill, they're going to be breaking down in an environment that is low in oxygen and that's going to lead to the release of methane, which is a greenhouse gas that contributes to climate change."

Mowing the leaves, especially with a mulching lawnmower, is an option because that deposits the carbon-rich leaves back into the ground without smothering the lawn and potentially preventing grass growing again in the spring. Reducing lawn size is something that Thomas practices, as she is using her property for more garden beds and layering them with leaves as compost. This is something recommended by the Pennsylvania Department of Conservation and Natural Resources to improve biodiversity, a topic discussed in the Environmental Issues class that Thomas teaches as part of SRU's online master's in park and resource management.

According to the DCNR, there are more than 2 million acres of lawns in Pennsylvania, a state in which about 80% of the land is privately owned. The DCNR encourages people to "share their yards with nature" and let go of the traditional lawns that are known as a "monoculture." Leaf litter provides winter cover for moths and butterflies, including the swallowtail butterfly that has a chrysalis disguised as dried leaves.

"If we want to make our yards more welcoming to different species, we need to provide the type of habitat that they require," Thomas said. "And by doing that, especially if you are interested in gardening like I am, you need pollinators that are going to help with food production."

But if you prefer to maintain your lawn, removing leaves is the way to go. Raking the leaves into your garden, using them for compost or taking them to off-site composting sites like the Macoskey Center are all great options.

The Macoskey Center staff use multiple types of composting systems which provide soil for the center's community garden and learning garden. There's a three-bin system made from wooden pallets that separate organic materials in the phases of composting process as well as a tumbler system made from a large cylinder. But the largest scale composting system are the three 100-foot-long "wind rows" located on a hillside between the Macoskey Center and SRU's Storm Harbor Equestrian Center.

Three times a week, pre-consumer waste from Boozel Dining Hall, such as scraps from chopped fruits and vegetables, are deposited on the wind rows, as well as materials gathered from community composting bins located on the side of the barn at the Macoskey Center. This includes everything from banana peels and coffee grounds to brown paper bags.

Macosky Center Community garden

   Macoskey Center staff spread compost at the center’s community garden.

"That all goes into the wind rows and those wind rows have to be turned over time," Laurence said. "It eventually develops into nutrient rich soil that we can use on our community garden and elsewhere on campus."

The wind rows are also where leaves wind up. In previous years, the Macoskey Center partnered with Slippery Rock borough to accept leaves that were collected by the borough, but the Macoskey Center still accepts leaves from community members as long as they call ahead between business hours, 8 a.m. to 4:30 p.m., Mondays-Fridays, at 724.738.4050. This is required so that staff can check the waste and direct people to the appropriate section of the wind rows. Non-leaves and organic materials that fit into the composting bins near the Macoskey Center barn, located at 247 Harmony Road, can be dropped off without calling ahead.

"Leaves can take about six months to decompose, so it's perfect for our winter to pass and by the time you're gardening in the spring they should be ready (for nutrient rich soil)," Laurence said. "The key factor to make the decomposition process go faster is water, sunlight and some heat, so it's really important to turn your compost every two to four weeks. Other things like fruit and vegetable scraps, especially cantaloupe or watermelon rinds, can take longer."

In addition to physical demonstrations of sustainable technologies and systems, the Macoskey Center supports sustainability-focused academic initiatives and research, and it provides education about sustainability through events. During the pandemic, the Macoskey Center has been offering virtual programs for the community, such as seed saving workshop hosted last month by Corie Eckman, a graduate student majoring in park and resource management program from Warren, who works as the center's sustainability education graduate assistant. Seed saving is another sustainable practice that gardeners can use to maintain a healthy life cycle, similar to composting.

For more information about Macoskey Center programs, visit the center's Facebook page. For more information about SRU's online park and resource management master's program, visit the program's webpage.

MEDIA CONTACT: Justin Zackal | 724.738.4854 |