Another Way to Grow Vertically: Outdoor Hydroponic Gardening

Another Way to Grow Vertically: Outdoor Hydroponic Gardening

Larry Johnson is a born systems thinker. While most of us might recognize a cog, Johnson not only sees the whole gearwheel, he knows what makes it turn. He understands how a set of factors and interactions contribute to a possible outcome. This is the guy who, when he was in seventh grade in San Antonio, built a cyclotron particle accelerator out of found materials. A Vietnam-era Air Force veteran, he worked in law enforcement when he got out of the service and got into computers. In the late 1970s, he built his own ultralight aircraft and flew it around San Antonio to advertise Miller beer. In the 1980s, he created Texas’s first long-haul telephone switching system (one in which long-distance calls are switched to connect a local central office). In the 1990s, he tested Microsoft Windows for Bill Gates early on in that product’s development and trained others in how to use its operating system. He still has his own Internet company. He’s made fortunes and lost them. The list could go on.

A couple of decades ago, he turned his inventive mind to gardening. The problem was, he killed everything he tried to grow. “I have the typical brown thumb,” Johnson says. “I was a total failure at gardening. I either overwatered, underwatered or forgot to water altogether.” He figured there had to be a better way, and, never one to give up on a project, he set about to create a system that would work for him.

Enter EZ GRO Garden, the company that he founded in 1997, which manufactures self-contained, fully automated, self-watering high-density vertical hydroponic growing systems. Marketed as complete kits, the systems are modular and can range in size from a single-tower unit up to those consisting of 1,000 towers. The smaller units (for patios, decks and backyards) are designed for home gardeners, while larger systems are intended for commercial use.

The system is based on a stackable pot that Johnson designed with four growing sections called a Quad Pot. Quad Pots attach to a support system dubbed the EZ GRO Tree, which is a tower that is connected at the top and bottom to form a stable grid. This setup is combined with water tanks, piping and plumbing to create a closed irrigation system. A nutrient-rich water solution comes in through the top of the tower, then water is pumped from the floor level and comes up inside the towers and cascades back down through the pots. Any unused solution is recirculated back into the reservoir for reuse.

Johnson enlisted Dr. Joe Masabni, the Texas A&M University Extension Vegetable Specialist with statewide responsibility, to test and evaluate an EZ GRO system designed to grow 700 plants in 15 towers in a footprint of two-feet wide by 18-feet long. “If this were in a field situation, that number of plants would have been a 300-foot row in length,” Masabni notes. “We did the math and can show growers that it may be a big initial investment in the system, but that is a onetime event. Think how much could be saved in field preparation, in tractor equipment, in plastic cost and such.”

One thing that Dr. Masabni studied was whether diseases were being transmitted through the recycled water/nutrient solution. “The common misconception is that if one plant is sick, all the rest would get sick because a disease will move in the water and infect everything else,” he explains. “We were able to prove that this doesn’t happen. The stock solution is concentrated enough so that it will not allow diseases to grow.”

Although just about any type of produce can be grown in Quad Pots, which are made of high-density polyethylene, their proprietary design and the sturdiness of the towers combine to provide support for even heavy fruit and vegetables. (The Quad Pots are manufactured in Hutto, Texas, and all system components are made in the U.S.A.) Johnson has 60 towers in his own yard, growing a remarkable variety of tomatoes, peppers, eggplants, squash, cucumbers and even cantaloupes. In season, his towers produce up to 400 pounds of tomatoes a week, which he sells in a stand on the road by his property and to the steakhouse up the road from his place.

The system automatically provides water to the plants for two minutes every hour for twelve hours. It takes five gallons of water one minute to go from the top pot to the bottom. Water is recycled, so there is no loss of moisture due to runoff. Plants are grown in a substrate mixture of coco coir and perlite, which can be reused and is a renewable resource. Sustainability is the underlying commitment of the entire EZ GRO system.

Johnson runs his own hydroponic garden off the grid, using another product of his own design called the Tri-Helix Solar Windmill — a set of solar panels mounted atop three rotating wind turbines made of aircraft-grade aluminum. The garden is outdoors, but in the heat of summer, he covers it with a highly-reflective aluminized shade cloth (called Aluminet) that reduces the temperature underneath by as much as 20 degrees. Pollinators move freely through the tower rows, and Johnson maintains that he has few pest problems because the plants are so healthy. While many EZ GRO gardens are installed outside, it is also possible to set them up inside a greenhouse for an extended growing season.

The EZ GRO website ( contains detailed information about each of the products offered, along with testimonials from customers ranging from individuals to schools, to food banks, to large installations in Nigeria and more. From Johnson’s home base in Red Rock, Texas (an unincorporated community in Bastrop County), EZ GRO Garden systems are sold all over the world — even as far as the Norwegian locale of Longyearbyen, the world’s northernmost town near the North Pole.

Johnson’s decades-long track record of success with his system provides a model that can be adopted by any gardener and adapted to grow a wide variety of plants. With land becoming scarce and water even more so, vertical gardening could be one answer to growing food sustainably.

By Suzanne Labry, B.A., B.ED.
Volunteer Billie L. Turner Resources Center Herbarium
University of Texas at Austin