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An Eater’s Guide to Hydroponics

What the heck is hydroponics? If this sounds like Greek to you, it is. “Hydroponic” is Greek for “water-cultivation,” and that sums it up well: hydroponics is growing plants in water instead of soil.

A hydroponic farmer plants their crops in floating rafts or in gravel-like beds, so the roots can float in circulating water. The farmer then adds oxygen, minerals, and nutrients to the water.

Sometimes these systems are built in greenhouses where there is plenty of natural sunlight. Other times they are built inside re-purposed industrial buildings, sometimes stacking multiple vegetable beds into a “vertical farm.” When natural sunlight is not available, farmers use energy-efficient LED lights to mimic the sun.

Aeroponic and aquaponic are two terms used to describe variations on hydroponic farming. These function on the same principle though, and you’ll be forgiven for not memorizing the vocabulary.

Today, farms in Ann Arbor, Lansing, and no fewer than five urban farms in the city of Detroit are growing their vegetables with hydroponics or other soil-less methods. These farms specialize in salad greens, microgreens, and herbs. Among those farms, are our partners Planted and Recovery Park.

Benefits of Hydroponics

The high-tech approach allows for year-round harvest, even during the Michigan winter when it is too cold and too dark to grow anything outside. Growing indoors also means that hydroponic vegetables do not normally need to be treated with pesticides.

Soil-less farming is highly water efficient, recycling its own runoff so that the fertilizers don’t create pollution in our waterways. It’s also incredibly space efficient which allows hydroponic farms to operate in dense urban areas. Closer to their customers, these farmers can deliver fresher produce and avoid the transportation required in a typical supply-chain.

Challenges of Hydroponics

Farmers debate about whether hydroponic farms can be organic. To many farmers, the word organic is deeply tied to natural, fertile soil and stewardship of the land. High-tech, factory-farmed lettuce just isn’t what they want to grow nor what their customers want to eat. The USDA disagreed in 2017 and officially allowed hydroponic farms to be certified organic.

Critics question the sustainability of hydroponic farms. They use considerable energy for their heat, cooling, lights,and water-pumps. A study from Arizona State University found that growing lettuce hydroponically required a whopping 8100% more energy than would be required to grow it in an open field. Some farms incorporate renewable sources such as solar panels, but in many cases this energy is coming from fossil fuels.

Taste-Test

Hydroponically-grown foods can be delicious, but sometimes just a little blander than their outdoor cousins. This is because crops grown indoors don’t develop as much sugar. In my experience, hydroponic salad greens wilt easily and should be used up within a few days of purchase.

According to research, the nutritional value is not very different from conventional produce. Studies have shown hydroponic vegetables to be lower in antioxidants but higher in vitamins. Either way, the differences were small.

In both flavor and healthfulness, the hydroponic vegetables make up the difference by being the freshest to market in winter and early spring. Your local hydroponic farmer can supply you with salad harvested only hours before!

Finding Your Farmer

The fundamental rule of hydroponic food is the same as any local food: know your farmer!

If there is a hydroponic farmer in your area, you can find them at your local farmers market or by searching on the Taste the Local Difference website. Shake hands with the person who grew those beautiful greens. Ask how they got into farming and why they chose hydroponics. Ask what they have done to make their farm more energy efficient. Most farmers will relish these questions, as long as you also support their business by making a purchase!

With hydroponics, the future is coming fast to Michigan’s food system. This new technology can deepen our local food economy and broaden the healthy options available to us, especially during the cold season. But, to make this future as delicious as possible, we’ll have to engage with our local hydroponic farmers and show them that we value their ingenuity.  

Nick Jones is the Local Food Coordinator for Metro Detroit. Contact him at
nick@localdifference.org

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