Sally Herbert's urban farm in Curtis Park uses less water and land to produce lettuce, arugula, and other greens for Denver's booming restaurant scene—and for your kitchen table.

BY CALLIE SUMLIN | NOVEMBER 2019

At the intersection of 25th and Lawrence streets in Curtis Park, on the second story of a building—high above the millennials zipping around on electric scooters and the yoga warriors exiting a nearby studio—sits Altius Farms, an 8,000-square-foot aeroponic greenhouse. Inside, small fans whoosh gently overhead and the temperature is always somewhere between 65 and 80 degrees. There’s a slight, almost pleasant humidity to the air and the fresh, clean mineral smell of lettuce. The clear polycarbonate roof diffuses and softens the Colorado sunlight, and glass walls make you feel like you’re surrounded by open sky.

Completing the urban Garden of Eden picture is Altius’ version of fields: 340 columns, each eight feet tall, from which sprout floppy green rosettes of butter lettuce, neon mustard frills, ruffles of baby red Russian kale, and lily-pad-like nasturtium leaves. The plants blanket the white, food-grade-plastic columns so thickly they look like edible topiaries.

Fifty-six-year-old Sally Herbert, co-founder, and CEO of Altius, walks through her fields, pausing often to pluck baby kale leaves or fronds of pink-tipped lollo rosso lettuce for sampling. The kale is mild and tender, the lettuce juicy and crisp. Nearby, a smiling intern snips baby arugula leaves into bins while farm manager Ethan Page and other staffers wash, dry, and package the day’s harvest. Assistant grower and account manager Brian Adams will soon deliver bags of the greens to Altius’ growing list of clients, which include Uchi (the farm’s downstairs neighbor), Il Posto, Butcher’s Bistro, and Marczyk Fine Foods.

There’s an efficiency to the way the staff moves that might make you think Altius has been honing its operations for many seasons. In truth, the farm’s been operating for a little over one year. In that time, the company has become a supplier for 40-some restaurants and luxury grocers, and it’s one of Denver’s largest hydroponic vegetable farms. It’s also the only aeroponic-specific facility producing food in Denver proper.

Aeroponics—which was popularized in the 1980s at Epcot’s Land pavilion in Walt Disney World—takes the principles of hydroponic gardening literally to the next level. As with hydroponics, there is no soil involved. In aeroponics, however, plants commonly grow out from vertical columns, not up from pots or beds. The plants’ root systems are housed in ports of spongy, inorganic growing mediums, which are popped into little openings in the columns. A gravity-fed, automated irrigation system pushes a pH-balanced, nutrient-fortified mist through the columns for three minutes at a time in 15-minute intervals, keeping the plants’ air-suspended roots moist.

The concept has become trendy around the world because these farms can produce food using up to 90 percent less land and water than traditional crops require and can be grown within miles—or even feet—of consumers. In 2018, GV (formerly known as Google Ventures) invested $90 million into Bowery Farming Inc., a New York-based brand that bills itself as “the modern farming company.” Everyone from IKEA executives to the sheik of Dubai has thrown money at AeroFarms, a similarly ambitious outfit in New Jersey. All provide answers to American consumers’ ever-louder demands for local and sustainable food. But the question remains: Can Herbert convince Denverites to join the movement and pay more for greens raised without soil?

Five years ago, Herbert had exactly zero farming experience when a friend recommended she check out Veterans to Farmers, a local nonprofit that trains former service members in traditional and hydroponic agricultural systems. Herbert, who served in the Air Force for 13 years (active duty and reserve), liked the group’s mission to provide veterans with fulfilling civilian careers and joined the board.

While helping a Veterans to Farmer’s trainee at his hydroponic operation in Lakewood in 2014, Herbert learned about controlled-environment agriculture and was fascinated. The timing was apt: Herbert, who typically dresses in plain T-shirts and the sort of breathable pants one might wear hiking, was burnt out as CEO of GS1, a global logistics company. She started researching farming trends and realized that Denver’s short growing season and proliferation of consumers who care about sustainability made it the perfect place for an innovative aeroponic operation.

Finding a location for Altius in the city proved challenging. “I needed a developer who believed in the cause and saw food production as an amenity to their site,” she says. When she connected with Westfield Company Inc. (the developer behind the S*Park complex of luxury townhomes and condos that encompasses Uchi and Altius) in 2015, things clicked.

As it turned out, the plot of land in Curtis Park had been a farm site before. (Elaine Granata, Denver’s grandmother of urban farming, had long coaxed peas and tomatoes from the ground there.) When the Denver Housing Authority sold the property to Westfield, it did so under the condition that the development includes a farming or green space component. Enter Altius. Where other new condominiums tout pools, S*Park’s tenants would have access to fresh vegetable subscriptions and events in the outdoor farm-to-table dinner space, making their “#gardengoals become a reality,” as the S*Park website promises.

With her location secured, Herbert needed funding to bring her vision to fruition. Despite the global interest in vertical farming and her business connections, she had no luck courting local investors. “There’s a lot of money floating around this town for tech startups,” Herbert says. “But trying to get someone to invest in an agriculture company? Forget it.”

It’s not surprising that some investors would be scared off by food production: Slim margins can mean a slow return on capital, and in a city where an acre of land can sell for upward of a million dollars, high-revenue businesses or development projects are preferable to farming’s modest profits. So, to get off the ground, Herbert financed the business herself.

In the midst of Denver’s brutal mid-July heatwave, Herbert’s plants are comfortable in their climate-controlled environment. Herbert, though, is outside, working in Altius Farms’ brand-new garden and event area. Just weeks ago, this ground-level space was a fenced-in rectangle of dirt. Now, it is fully built out with raised beds and long communal tables, ready for ticketed farm-to-table dinner events.

Herbert, her shiny, dark hair pulled into a low ponytail, hunches over one of the 15 soil-filled beds to carefully prune a tomato plant. Nine months in, things are going well at Altius: Through trial and error, Herbert’s team has figured out which varieties of seeds work best in the indoor tower environment. High-end restaurants all over town have begun to name-drop Altius’ greens, herbs, and edible flowers on their menus. And the farm has donated hundreds of pounds of produce to nonprofits We Don’t Waste and SAME Café.

But it is not enough to turn a profit—yet. It’s still difficult to convince a grocery shopper to pay $4.99 for a clamshell of salad mix when they can get a head of lettuce for less than $2 at King Soopers. “Farming is the hardest thing I’ve ever done,” Herbert says. And that’s even with Altius’ automated irrigation and temperature control systems, the polycarbonate roof that prevented a June hailstorm from shredding her crops, and a strong customer base.

Because, at the end of the day, it’s still farming. It’s still waking up in the middle of the night panicking about the crops. It’s still having to convince folks to buy a premium local product and coaxing nature into a business model. The aeroponic system has drawbacks, too: The towers aren’t suitable for growing root vegetables, and proponents of organic produce tend to frown upon the aeroponic method, which requires plants to be fed liquid nutrients.

Another challenge, which Herbert has grappled with since the beginning, is that the arrival of Altius in Curtis Park meant the displacement of other farmers; Granata now grows at a small space abutting a parking lot at the UCHealth University of Colorado Hospital. Herbert is conscious of the fact that to some, her aeroponic farm is just another sign of a gentrifying neighborhood. As such, she seeks ways to better serve the surrounding area (donating produce to Comal Heritage Food Incubator) and to support other farmers (continuing to serve on the Veterans to Farmers board).

While Herbert is surprised at just how many setbacks have arisen, she’s still confident in Altius. Just as she trusts her seeds will sprout, she says that the farm is on track to profitability. Her lofty goal—to potentially put locations in Denver and cities across the country—feels distant but possible. In the meantime, she pauses to wipe sweat from her brow and survey her work, just for a moment, before heading back to the greenhouse above.

CALLIE SUMLIN, CONTRIBUTOR

Callie Sumlin is a writer living in Westminster and has been covering food and sustainability in the Centennial State for more than five years.