It wouldn’t make much sense to attempt growing wheat in tiny plots scattered all over the city. However, roof top space makes urban farming grains a concept worth considering. It grew beautifully on top of a building in Chicago, proving that you can increase the diversity of locally grown crops quite a bit. Not to mention being a history making project that began by accident. Interesting, but is it feasible? Let’s investigate!

It began with a green roof installation for people and pollinators atop the offices of architectural firm, Studio Gang, that included a wildflower meadow. But it was a little late to start the meadow plants last year, so it was decided to keep the soil intact over the winter by planting an annual cover crop… wheat. Hard Red Winter Wheat, to be precise. As a trial roof top farming crop, the results were pleasantly surprising. Grasses do well in this environment, which is what a cereal crop is. The rooftop garden company, Omni Ecosystems and their sister company, Roof Crop, harvested the ripe wheat late this summer by hand… using scissors.

So, what was the crop yield? Over 60 pounds, a little more than a bushel of high yielding wheat. That doesn’t sound like very much of a harvest, but don’t dis urban farming grains just yet. The entire rooftop prairie planting, including shrubs, trees, perennials, and vegetables covers a total of 5,000 square feet. The meadow space occupies 1,000 square feet, and the wheat’s purpose at planting time was only to stop the growth media from blowing away. No one ever considered making use of it at the beginning. They were going to install the meadow once spring rolled around. The next wheat field Omni and Roof Crop plant they’ll probably get a better harvest, because making excellent flour will be the purpose. They’re already looking forward to planting wheat somewhere next year.

But how does their accidental harvest stack up against the average wheat field?

The Numbers

It’s likely most yield data you find online for this crop are from conventionally grown wheat, and this urban farming grains experiment was organically grown. It does make a difference. Organic wheat has a lower per acre harvest… 32% less, according to the USDA. The available data gives an average of 30 bushels per acre based on farm yields in 2009. Per thousand square feet that gives us an average yield of 1.45 bushel, so they’ve got poor production levels. Perhaps if they hadn’t planted clover with the wheat, there would have been more wheat berries to harvest. Think crop rotation… wheat, then clover, then wheat again. Very doable with winter wheat, without needing a fallow year.

Roof Top Wheat Harvest: Urban Farming Grains

Under planting with clover definitely decreased harvest yield. (Courtesy of Studio Gang)

Granted, 1/45th of an acre isn’t much of a wheat field, but still, that’s an awful lot of scissor snipping! Some enterprising soul needs to invent the roof top cereal harvester. A miniature combine that can cut the stalks, and suck the harvested grain heads into a suitably light weight container on wheels. It’s not like such a piece of equipment exists – no one has ever grown wheat on a roof top before. This project however, might just be the first in a whole new trend. Especially after some ingenious tinkerer engineers the means of mechanizing the harvest.

Food Security

The reason for low roof top wheat yield? Poor crop planning!

With better crop planning, roof top wheat fields can equal, maybe even exceed organic farming averages. (Courtesy of Urban Habitat Chicago

A bushel makes a surprising amount of flour. According to the Washington Growers of Wheat Association – 1 bushel of wheat creates 42 pounds of white flour. That’s enough to make 42 pounds of pasta, or 63-74 loaves of bread. Why such a spread on how much bread it makes? It varies by the loaf size, and also by whether it’s white or whole wheat. They also report that a family of 4 could live for 10 years off one year’s harvest yield from an acre of wheat. Not that man can live on bread alone, but a little goes a long, long way. That is if urban farming grains produces the right kind of flour for making bread. Crop planning is needed.

There are several kinds of wheat, and they’re not all the same. Spring wheats are planted in spring and harvested in fall. Winter wheats are planted in fall, the crop sprouts and grows a good root system before going dormant for the winter, and is ready for harvest by mid-summer. Winter wheat has a bit heavier yield than spring: 82 bushel per acre versus 78 (conventional growing). Each has specific foods it’s best for making. All wheat is divided into 6 classifications, and each has specific foods it’s best for making.

  • Soft White Wheat is used mainly for bakery products other than bread, due to it’s low protein content and weak gluten. Best for cakes and cookies, pastry, cereals, crackers, and flat breads.
  • Hard Red Spring Wheat is an important bread wheat with strong gluten and high protein content. Best used for mass-produced pan breads, and artisan breads or rolls.
  • Hard Red Winter Wheat has medium protein content and mid-strength gluten. Best used in making Asian noodles, flat bread, and general purpose flour.
  • Durum Wheat is planted in spring. It’s the hardest of all, and makes superior pastas. It’s also used to make couscous, and Mediterranean breads. Most Durum is grown in North Dakota and Montana.
  • Hard White Wheat is used for making Asian noodles or breads. It’s a popular crop in the Central U.S. states with both spring and fall planting varieties.
  • Soft Red Winter Wheat is particularly high yielding used in making many different foods, including pancakes, crackers, and pastries. Most of this wheat is grown east of the Mississippi River.

From Field to Cookies

Once it was harvested, the roof top wheat was threshed and winnowed by kids in an after school program at Urban Habitat Chicago. And finally milled into flour. The kids didn’t know that wheat is what flour is made of before being involved in this project. A great learning experience, one that many more youngsters should have.

How did the quality of the roof top grown wheat harvest measure up? It was great quality. Local bakery, Baker Miller turned it into reportedly fantastic chocolate chip cookies. Though co-owner Dave Miller thought they were all nuts when they approached him about turning their flour into food. Just because you grew wheat doesn’t mean it’s human food quality – it could make you sick! But, it tested toxin-free. Not only did Dave join the group of pleasantly surprised people involved in this accidental farm project, he finds the whole idea of growing wheat on top of Chicago buildings extremely intriguing. He’s got his thinking cap on. And Studio Gang? They were amazed at how beautiful the wheat was, and finds their part in making history very exciting.

Hyper locally grown wheat. Just think what artisan bread makers, bagel shops, muffin magicians, and the like could do with that! Why stop at wheat? What about oats, buckwheat, rye, spelt, and all the remaining cereal crops? Think heirloom varieties with reduced gluten content. So many possibilities for those many acres of rooftops in big cities, urban farming grains will likely start popping up everywhere. There will be a market for growing them under contract for discerning bakers, chefs, and possibly even microbreweries or local distillers.

Improving crop yields will come with experience. If Baker Miller is plotting to incorporate hyper local wheat into the baked goods and product lineup, the competition will want to get in on it too. Someone needs to create a mechanical harvester that can ride to the roof in an elevator, and make short work of the harvest. Then there’s the need for mechanical threshing and winnowing for reasonable production of flour. And we need to grow both bread and baking flour wheats. The real challenge might be growing Durum Wheat for pasta beyond the northern plains where the environment produces the best quality durum flour.

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Amber

Amber

Contributing Writer at Garden Culture Magazine
The garden played a starring role from spring through fall in the house Amber was raised in. She has decades of experience growing plants from seeds and cuttings in the plot and pots.
Amber