Last Saturday morning, Rene Gelder stood behind her produce stand in the back corner of the large khaki-colored tent at the Peggy Notebaert Nature Museum.

A few last customers perused the table and made their purchases, while a man holding a canvas shopping bag stopped to pick Gelder’s brain on some nuanced topic regarding apple harvests.

Aside from some eggs and a small selection of honey, Gelder’s edible wares consisted mostly of the apples grown at her family farm in Benton Harbor, Mich. The varieties included honey crisp, Swiss gourmet, fuji, granny smith and mutsu — the last of which she had run out of earlier in the day, due in part to the comparatively small yield that the Ellis Family Farm puts out of the apple.

But as the market neared its 1 o’clock closing time, the Ellis Family Farm stand still had a considerable stock on hand.

That’s how it’s been for most of the early winter season, said Gelder.

“I’ve heard that from a lot of farmers in the winter time this year, we’re not sure why,” she said.

Started in the early 1940s, the Ellis’ family-owned farm has been working city markets in the Midwest for nearly three decades and has been selling at Green City for about six years. Gelder said she comes to Chicago primarily to sell to restaurants, but makes a point to run a table at the Lincoln Park non-profit market, which boasts the title of being the one of the only farmers markets in the city that stays open in winter time.

Even though business has been a bit slow at the onset this season, Gelder said that sales in Chicago trumped those at the roadside stands in rural Michigan.

“The markets in Benton just are not comparable,” she said. “We don’t have the population.”

When the weather gets chilly, Gelder said, there wasn’t a better farmers market to hawk produce than at Green City.

“In the winter, it’s the only game in town, really,” she said.

Founded in 1998, Green City has become one of Chicago’s standout markets for customers looking for organic produce and meats from regional vendors. In 2010, the market recorded as many as 200,000 visitors at its summertime location on the south end of Lincoln Park between Clark Street and Stockton Drive, and at the Notebaert Museum, located 2430 N. Cannon Drive, where it sets up camp for the winter. That number has spiked from just from 40,000 visitors in 2007.

In response to this surge in customer traffic, this year the market expanded its winter hours from two Saturdays a month to every Saturday.

“We wanted the continuity for the farmers, and they said they would have the product every Saturday,” said Green City Executive Director Dana Benigno.

The market also extended its space at the museum, opening an additional tent on the museum’s second story balcony to accommodate the growing pool of vendors and visitors.

Benigno lent the market’s continued success to an increased interest in sustainable food production among customers, as well as Green City’s efforts to make the market financially accessible.

In 2010, in keeping with farmers markets run by the city, Green City began accepting the Illinois LINK card — Illinois’ food stamps program — from customers who receive financial food support from the state. Benigno said that the market’s number of LINK-carrying customers doubled in 2011 from the previous year.

“We hope to grow that, because its business for our farmers, and it makes what we are doing accessible to everyone,” she said.

While the trend of buying local seems to be showing no signs of ebbing, some failing markets in Chicago have indicated that farm-direct food doesn’t always sell itself.

This year saw the cancellation of at least four city-run markets — including those at Trump Tower, Pritzker Park and Erie Street — that couldn’t show enough profits to keep farmers and customers coming back.

Yescenia Mota, the special events coordinator for the city’s Department of Cultural Affairs and Special Events, said that identifying a formula for a successful farmers market wasn’t easy — but a supportive resident base was a good start.

“When the community doesn’t embrace the market, obviously the farmers aren’t going to make any money and they won’t return,” she said. “You need a very active community.”

Mota said most of the markets in Chicago remained profitable in 2011, adding that the Mayor’s office would announce locations for five new farmers markets in the city in the coming weeks.

Though Green City’s expansion does mark an increased interest from foodies, Benigno said that the market was not entirely exempt from the wide-spread symptoms of consumer belt-tightening.

“Our sales fluctuate up and down with the economy, just like any other business,” she said. “But we’ve had really strong years, and I expect that to be the case moving forward.”

The Green City market is open every Saturday at the nature museum from 7 a.m. to 1 p.m. The market returns outdoors in April, with stands selling on Wednesdays and Saturdays during the same hours.