The weather is harsh and gray, but inside the seed processing workshop at the Rollins Savanna Forest Preserve near Grayslake, the focus is on spring fields bursting with the color and variety of native plants.
A small, dedicated group of volunteers braved frigid temperatures on a recent afternoon to be here. Twice a week from early November until the job is done -- usually in February -- nature-loving volunteers painstakingly remove stems, leaves and chaff to access tiny treasures that will be sown to enhance the landscape throughout Lake County.
"You put it there for others to enjoy. It will go on for generations and generations," explained Ann Kohler, a retired elementary school teacher who has been volunteering with the Lake County Forest Preserve District for about seven years.
"It's not for the here and now; it's for posterity," she said of the fruits of her labor.
Today, the priorities are prairie violet, a ballistic seeder that is new this year; nodding fescue, a type of grass; common woodrush, a grasslike plant; and willow aster. All are native varieties you won't find at the local home improvement store.
In a practice that occurs throughout the region, the seeds of native plants are collected and used for a variety of projects, such as restoring woodlands, transforming former farm fields to prairies, or enhancing existing natural areas.
"They're part of a big network doing this work," said Kayri Havens, director of plant science and conservation at the Chicago Botanic Garden.
Chicago Botanic is among six botanic gardens throughout the U.S. participating in "Seeds of Success," a national program with the U.S. Bureau of Land Management. As a member, Chicago Botanic collects and banks plant species from 12 Midwest states to be made available for restoration programs.
Havens explained the native habitat restoration is essential to providing ecosystem services, such as purifying the air, sequestering carbon and providing a habitat for wildlife. At about 75 years, the field is fairly young but evolving.
"I think it took biologists a while to recognize the damage done by invasive species," she said.
Whether starting from scratch or improving what's already there, the purpose is to return the land to historical conditions, said Jim Anderson, natural resource manager for the Lake County Forest Preserve District.
Collected primarily in the fall from the 5-acre native plant nursery at Rollins Savanna and the district's vast land holdings, the seeds of native grasses, wildflowers and other local plants are used in mixes to enhance or start new prairies, woodlands and wetlands.
Getting to that point requires several steps. This time of year, the thrust is on cleaning the seeds so ecologists who plan the restorations know how much of various species are available for different uses.
Removing the excess bulk to ready millions of native seeds is admittedly low-tech. Inventory is stored in paper bags. Workstations are cardboard trays, and volunteers pull handfuls of plant material from plastic sandwich bags to run through homemade wooden sifters.
A machine is needed to separate some of the seeds, but there are finishing touches, too.
Kelly Schultz gently shook and blew on the seed of a woodrush -- about the size of a grain of pepper -- to demonstrate how to isolate the seed for use. "It's slow, but it works," she said.
As coordinator and sole staff member of the forest preserve district native seed nursery, Schultz oversees a year-round operation and educational program that in 2012 produced 360 pounds of seed -- representing an estimated 500 million individual seeds -- from about 200 plant species.
Some seeds, such as the wild flower Lobelia, are so small it takes 900,000 of them to equal an ounce, she said. Others, like the wild yam or woodrush, are priceless, meaning they aren't sold commercially.
"You cannot buy these, so don't sneeze," she tells a visitor.
The nursery provides about one-third of the seed needed for restoration projects. The book is still out on the 2013 harvest, though it looks to be substantial.
"We had a really big harvest this year," according to Schultz. "We keep increasing the number of beds we have and the number of volunteers."
Part of the reason the district established the native seed nursery in 2005 -- and among its biggest contributions -- is to provide access to rare local plants that are too costly to buy or unavailable. There are 140 species in the native plant nursery and about 240 species throughout the forest preserves.
For example, Schultz said she was excited this year to collect yellow star grass seed, a delicate plant, whose tiny green pods get lost under much taller prairie vegetation. An ounce contains about 80,000 of the yellow star seeds.
Schultz said she also has been working with the Chicago Botanic Garden's Plants of Concern program, which focuses on rare, threatened and endangered species. The district successfully has grown about two dozen of those species and collected and sown seed from another dozen species, she said.
One example is the stalked water horehound, a wildflower that was found in a single forest preserve. It will be a good fit for a project to restore oak woodlands along the Des Plaines River in southern Lake County, she said.