In a free Thursday evening webinar, local nonprofit organization Sustainability Matters will finish its two-part program “Composting for the Clueless” with tips on how to build a compost pile using materials you have at home.

Adding compost to a garden helps add nutrients to the soil to grow better vegetables and other plants, said Clarke County resident and Sustainability Matters member Deborah Abercrombie, who led Part 1 of the program earlier this month.

Composting can be relatively easy once you start, but it takes a while for it to become useful, said Abercrombie, 62, who grows fruit and vegetables to use for canning.

Cold composting takes a year or more of adding ingredients, mixing and waiting until the materials decompose and form a natural fertilizer, she said.

But when it’s ready, you’ll know.

“It smells like a walk in the forest after a rain,” said Abercrombie. “It’s just a delicious smell.”

Composting is a soil amender.

“It changes your soil structure,” she said. “Whatever soil you have, compost helps it be better.”

Abercrombie composts pretty much any plant materials she can, from rotten vegetables to branches fresh from the woodchipper.

Grass cuttings, weeds, dried leaves, mail, shredded newspapers and wood ash can also be added, she said, as well as eggshells.

Just be sure not to add products that include herbicides or other harmful chemicals, because those will kill your garden vegetables, she said, and if adding paper towels, don’t use any with baking grease.

Abercrombie also doesn’t include processed foods or bones so that she won’t attract predators to her property where she keeps chickens, turkeys and domestic ducks.

For the beginner, she suggests homeowners do a soil quality test to determine what type of soil they have and which composted items will benefit it.

Before composting, “You should always know what you need,” she said. “To really make your Virginia clay not Virginia clay.”

Abercrombie’s recent webinar boasted about 650 attendees from around the world, including Australia and Europe, said Sari Carp, executive director of Sustainability Matters.

“It was just a really fantastic, engaged audience,” Carp said.

For those who missed it, the webinar link is available on the group’s Facebook page, facebook.com/groups/SMCompost, and Carp said the event page will remain open indefinitely for visitors to share ideas and ask questions of the program organizers.

Part 2, “DIY Composter Building for the Clueless,” from 7 to 8 p.m. Thursday, is free and open to everyone.

Though highly useful for gardeners, composting is a subject that people can find daunting, Carp said.

“We just wanted to demystify it for people,” she explained. To build a composter, she said, “You don’t have to spend anything.”

Composting at home can save people money, she said, “because compost is expensive when you buy it.”

Furthermore, it helps save unused food that otherwise might go to the landfill.

“Thirty percent of landfill waste nationwide is food waste,” Carp said. “[That’s] actually food that could be composted.”

At its roots, however, composting improves gardens.

“Vegetable gardening is harder than it looks,” Carp said.

“This is a great way to improve your soil [and] improve it for free without having to go buy compost.”

“Composting for the Clueless” is funded by a $16,000 grant from the Virginia Department of Environmental Quality, which covers the two webinars, the Facebook page and marketing for the program, Carp said.

Leading the second webinar will be Michael Neese, refuse and recycling manager for the City of Winchester, which is also partnering on the project.

“[He’s] one of the most intensive composters I know,” Carp said.

When Neese didn’t have access to the outdoors for a composter, she recalled, “He used to compost in his living room.”

Sign up for Thursday’s webinar at buildcomposter.eventbrite.com. Attendance is free, but advance registration is necessary to receive a Zoom link.

Contact Josette Keelor at jkeelor@nvdaily.com