Creating and Maintaining a Roof Farm at Chicago’s Uncommon Ground
Editor’s note: This is the second in a series of three articles about restaurant gardens and farms. Click here to read about small space/intensive gardening at Houston’s Coltivare, and check back next week to learn how Edward Lee and Kevin Ashworth built a greenhouse at Louisville’s 610 Magnolia.
The Roof Garden at Chicago’s Uncommon Ground isn’t just a side project for owner Helen Cameron; it was the first certified organic rooftop farm in the U.S. when it was built in 2008, and is famous enough to have its own FAQ page on the restaurant’s website.
“This is a working farm, not a garden,” Cameron emphasizes about the 2500-square-foot space. “The restaurant is the customer. But it’s also part of our scheme to support a better foods system in the Midwest.”
Cameron spotted the rooftop’s potential to support that mission when she and her husband, Mike, first looked at the building that houses the restaurant and farm located on the north side of the city.
“We were looking to purchase the building, and wanted to check the condition of the roof,” she recalls. “We came on a sunny day in February, and I climbed up there. As soon as I cleared the wall, I saw this wide-open silver space, in glorious sunlight. The first thing that came to my mind was a big red tomato. Mike climbed up, and we determined two things: We would definitely use the roof to grow food, and we’d do solar energy up there. We bid on the building after that.”
Building the rooftop farm was anything but easy. Or cheap. Since the building was over 100 years old, the Camerons first had to hire a structural engineer to help them figure out how to make it so the roof could handle a farm and thousands of pounds of soil (they have 654 square feet of soil up there). After learning that roof could not support the weight they needed, they dug out the basement, creating larger footings for the building and installing steel supports. Once the building structure was reinforced, they created a steel grid system on the roof, and built a deck to float on top of that grid, so that the weight of the deck and the planter boxes that came next would be more evenly supported.
“It was a pretty big investment,” Cameron admits, adding that a $20,000 grant from the city of Chicago helped fund the project. “We were able to get assistance, Tax Increment Financing from the city, that really helped us. It increased the price of the project, but was also what helped make it happen.”
The benefit of all the work is that the roof is in better shape than ever, now that it is shaded. “The plants are creating a cool surface, so that’s better for the roof,” Cameron notes.
She and her gardening team designed trellises and a drip irrigation system for the roof’s planter boxes (which are on wheels to make moving them around the roof easier), and began planning.
Rooftop gardens are usually cooler than ground level, some a full zone cooler than ground level on the USDA Plant Hardiness Zone map. On a roof, wind stress becomes a factor, and delicate plants need extra care. Cameron and her team plant sweet and hot peppers, lettuce and other greens, tomatoes, radishes, beets, eggplant, fennel and okra, and herbs including rosemary, garlic chives, sage, parsley, dill, lavender and basil. They also grow what she calls companion plants, including flowers like calendula, marigolds, sunflowers and nasturtiums.
As large as the roof farm is, to grow enough produce to support their two restaurants means following square foot gardening methods to maximize production, and be mindful that they are farming in boxes, not the ground. The boxes are 12 inches deep, so they must grow plants whose root systems don’t require anything deeper.
The farm was designed to be certified organic from the start, so Cameron connected with organic farmers to learn how to make the farm as productive as possible with fertilizers like fish emulsion instead of chemicals. She says they dedicated the first five years to experimentation, to understand what they were dealing with and find a system of raised bed farming that would be successful for production. She passes that knowledge to others, emphasizing the importance of biodiversity and crop rotation so that the soil’s nutrients aren’t depleted.
It was a lot of learning, trial and error, but she says a lot of it is just “good simple wisdom” to rotate crops between boxes and plant produce like peas, which help fix the nitrogen levels in soil. She and her team plant cover crops like hairy vetch in the fall to replenish the nitrogen lost from that year’s tomato plants.
“I have an idealistic side to myself, and we do act on our idealism,” Cameron says. “It does require a lot of time and effort to do it and do it well. When you plant a seed, you’re growing a creature that requires care and attention. You have to have a reliable person in charge of it. I’ve been fortunate to have farm directors and people who care about it.”
For all the work it required, the rooftop farm has made running a restaurant even more meaningful for Cameron, who has added bee hives to the rooftop to further support the farm and larger Midwestern ecosystem while supplying honey for the restaurant.
“As a restaurateur, I didn’t think about how much time and effort a farmer puts into growing food for me, but that’s something I appreciate now,” she says. “It seemed like an obvious thing to me, to have a restaurant and grow produce for it,” Cameron says. “We grow food, take it downstairs and serve it. It’s a lot, but it’s also very simple.”