The Wild Roots student-run garden is located outside the Norris University Center on the Northwestern University campus. Photo by Ava Hoelscher / North by Northwestern
Olivia Shenker, a Weinberg High School senior, loves the earth. The biology and environmental policy and culture major says the environment has encompassed her entire life, from living vegan for five years to focusing on policy in her future career. One of the ways she supports sustainability at Northwestern is through Wild Roots, a student-run garden on the university's campus.
Schenker is a dedicated traditional grower at Wild Roots, but along with other members of the organization, he plans to pivot to an innovative form of gardening called hydroponics, which Wild Roots embraces.
According to the United States Department of Agriculture's National Agricultural Library, hydroponics is a technique for growing plants using a water-based nutrient solution instead of soil.
“It's like a system where the water is constantly flowing, and you don't need soil,” Schenker said. “The plants just grow out of the water.”
Rachel Silverman, a sophomore industrial engineering student at McCormick, is co-vice president of Engineers Without Borders, a student group that uses engineering to promote sustainability, and their latest project is partnering with Wild Roots to build a hydroponic growing system.
Silverman said hydroponic systems are beneficial for the environment because they deliver water directly to the plant's roots.
“Soil degradation causes soil to be lost faster than it is created, so having alternatives that allow you to grow crops without soil is really important,” Silverman said. “Secondly, it uses significantly less water than normal plant cultivation because you don't have to let the soil percolate and you can recycle the water through the system.”
Hydroponic systems work in cycles, pumping water from nutrient-filled water sources into the growing trays and then back into the solution tank to add more nutrients. For an average-sized hydroponic structure, the nutrient solution is typically changed every two to three weeks, according to Floraflex. When growing indoors, you need an energy source to provide light for your plants and pump water.
Engineers Without Borders and Wild Roots, an effort led by Silverman and Julianna Gonzalez, a sophomore manufacturing and design engineering major at McCormick, are ironing out those technical details. Silverman said she and Gonzalez weren't familiar with horticultural alternatives like hydroponics before Wild Roots reached out to them, but once the two organizations connected, Engineers Without Borders looked into the system and decided to take on the project.
“I think you learn a lot more by doing it, and by joining this club I've learned a lot more about the different solutions that exist,” Silverman said.[I am] We just want to better understand the current state of the environment and how we can help.”
Once Engineers Without Borders agreed to work with Wild Roots, they put together a rough design and discussed logistics with Wild Roots advisor Corbin Smith. The final sketch is for a 6-foot-long, 4-foot-wide structure with plants arranged horizontally above a basin of water. While many hydroponic structures have lights installed on top to control plant growth, this system doesn't need lights because it gets natural light outdoors.
“They ended up sending us the materials. [list] “We resubmitted our paperwork, redid our materials and sent them back to our advisor, who sent them to SOFO,” Gonzalez says. “This whole process took a very long time, and it was very frustrating, to be honest.” But the process and patience paid off.
Gonzalez said the students decided to only choose Home Depot items when recreating their materials list because Home Depot is approved on the SOFO platform. Engineers Without Borders originally planned to open the building to the public in late May 2024, but due to delays, Gonzalez said they will postpone the start of the project until next school year. She said that even with the delays, she believes the hydroponic system makes enough sense for the university that the students are sticking with the plan.
Gonzalez said the hydroponic system will raise awareness about water consumption and waste on campus, adding that sustainability is a big part of the world now and incorporating it into an engineering project is very interesting.
Eric Weber, director of operations at Plant Chicago, said they are taking the sustainable aspects of hydroponics and building on them. Plant Chicago, located on Chicago's south side, introduced hydroponic and aquaponics urban gardens in 2011 when the organization launched. The first system was installed in The Plant, a former meat processing warehouse that welcomes a supportive community of small food businesses, according to The Plant's website. Plant Chicago relocated its hydroponic and aquaponics facility a few blocks away to its current location in 2020, Weber said.
According to Nelson + Paid, hydroponics is part of an aquaponics system that draws naturally fertilized water from a fish tank, pumps it through plants growing in the water, purifies the water, and then returns it to the tank. Fish waste fertilizes the water, and special bacteria in the water break down ammonia in the waste that's harmful to the plants.
Weber walked around Plant Chicago's indoor space, which is filled with a number of hydroponic and aquaponic towers of various sizes. In the aquaponic structures, fish swim lazily at the bottom level and a series of pipes lead to neat rows of plants growing in water. Weber said the main advantage aquaponics has over hydroponics is that it can grow fish in addition to plants.
“In addition to vegetables, you have a potential protein source that you can harvest and eat,” Weber says. “You treat the system as its own living organism. You have fish and you have plants, and you try to keep them living in harmony with each other.”
According to Weber, the nutrient source in a hydroponic system is very different from that in an aquaponics system. In a fully hydroponic setup, the plants rely on synthetic fertilizer rather than organically treated fish waste. This leads to one of the main criticisms of hydroponics, according to Weber.
Critics of hydroponics don't consider it organic, preferring more natural methods, Weber said. The United States Department of Agriculture (USDA) doesn't mention soil cultivation in its definition of organic, but the USDA does state that “the cardinal rules of organic agriculture are that natural substances are permitted and synthetic substances are prohibited,” according to a subsection of its website called Organic 101. If hydroponic or aquaponics systems don't use synthetic fertilizers, the USDA allows them to be certified organic.
But the defining feature of organic produce is that it's grown in soil, according to the Real Organic Project. Weber acknowledged that in both hydroponic and aquaponic farming, plants are grown in a controlled environment rather than left to their own devices.
“You're trying to control as many parameters of the environment as possible: light, temperature, humidity, airflow, oxygen, the amount of carbon dioxide,” Weber says. “All of this requires some form of technology and electricity, which tends to be quite expensive. Depending on the power source and in different parts of the world, the environmental impact and costs will vary.”
Weber said the “intuition” behind these technology-based growing methods is to properly weigh the costs and energy usage against the benefits of the system. Some gardening enthusiasts can build a small home hydroponic system for a few hundred dollars, but the cost of a system can run more than $10,000 depending on the customization of size and energy needs, Weber said. Some structures, like Plant Chicago's system, rely primarily on renewable energy sources. Plant Chicago's system runs on a 16-kilowatt solar array that was installed on its roof more than a year ago. But some can store energy from non-renewable sources, such as coal and natural gas, Weber said.
Opponents such as the Real Organic Project consider hydroponics' potential cost and energy-related downsides, ruling it out as a sustainable option. Weber takes a more holistic approach. They say multiple factors must be considered when implementing hydroponics, including what crops grow naturally in the area, what financial resources are available, and whether renewable energy is readily available. And in a world where droughts are expanding due to climate change, hydroponics recycles water.
“Just as easily as you can say, 'Hydroponics will save us from world hunger,' these broad strokes can be used to say, 'No, this is awful, it's a huge waste of space and time and money and electricity,'” Weber says. “I don't think either is correct.”
Weber said he would never set up a giant greenhouse in Florida to grow trees indoors, because the state's climate is ideal for growing trees naturally outdoors. He might consider growing leaf lettuce in Nevada using indoor hydroponics, however. The state's desert climate would require much more water to irrigate the fields than growing the plants in a nutrient-based water solution. In that case, there would be much less overall water loss, a clear advantage to growing crops in a desert environment, Weber said.
Kelly Fleming, branch assistant at the Evanston Public Library's Robert Crown branch, said that while hydroponics may not necessarily be sustainable, it still provides a great resource. She implemented a hydroponic system rental program at the branch two years ago, allowing patrons to rent the small structures for free for 11 weeks at a time.
Fleming said hydroponics is a great option for people like him who live in apartments and don't have much access to green space. He added that in urban areas, soil can contain lead and other heavy metals, making it impossible to grow healthy crops. Indoor hydroponics can give people better access to fresh produce in those conditions, and they can even grow out-of-season vegetables and herbs. Fleming said he doesn't dismiss the benefits of hydroponics just because it's not organic.
The Robert Crown Branch of the Evanston Public Library not only lends out small hydroponic systems to patrons, but also has a larger structure on display in the building. Photo by Ava Hoelscher/North by Northwestern
“If it's grown sustainably, does it matter if it's organic?” Fleming says. “As long as people are growing it, that's great.”
Shenker also dislikes black-and-white criticism of hydroponic systems: To her, there are good and bad things about everything, and giving people more options for growing plants in different situations is a move in the right direction, she says.
“I'm not saying we should go all-in on hydroponics, I think that's unsustainable,” Schenker says, “but given that people have so little access to good, clean food today, it's great to implement diverse solutions.”
The hydroponic system, developed by Engineers Without Borders and Wild Roots, is scheduled to be tentatively installed outside Norris University Center in 2025.
Silverman said the system will have a QR code with information about hydroponics so students can learn more about why the structure was built. She said she thinks the project will spark environmental awareness on campus.
“We hope it will spark interest in sustainability-focused tools,” Silverman said, “and maybe spark a conversation about other ways to be more environmentally conscious.”
