The shipping container sat in a London parking lot, its industrial metal exterior hiding an unexpected world inside. Stepping through the door revealed a humid microclimate where emerald lettuce leaves unfurled under purple LED lights, while below, tilapia darted through tanks, their waste becoming the nutrients that fed the plants above—a miniature ecosystem contained within corrugated steel walls.
For Kate Hofman, this wasn't just an agricultural experiment—it was the physical manifestation of a career pivot that would transform UK food systems. "The GrowUp Box was our proof of concept," Hofman explained. "We needed to show people that vertical farming could work in the UK—not just technically, but as a viable business."
As the UK heavily relies on imported salad and faces challenges in domestic production due to climate disruption and rising energy costs, Hofman's GrowUp Farms has achieved what many vertical farms couldn't—profitable, sustainable production at scale with major retail distribution. Her journey from IBM consultant to agricultural innovator offers a blueprint for scientists seeking to transform experimental concepts into commercial reality.
Corporate Roots, Agricultural Dreams
Before Hofman grew lettuce, she cultivated organizational change. At IBM, she managed large-scale business transformation programs, helping corporations navigate complex transitions. This experience might seem worlds away from agriculture, but it provided the systems thinking foundation that would later distinguish GrowUp Farms from other vertical farming startups.
"At IBM, I learned how to manage stakeholder engagement and structured approaches to transition," Hofman explained. Those skills turned out to be essential when building agricultural systems that had to satisfy multiple stakeholders—from investors to retailers to consumers.
During a sabbatical, Hofman pursued a master's in Environmental Technology at Imperial College London, where she discovered aquaponics—a system combining fish farming with hydroponic plant cultivation. This intersection of technology and sustainability sparked her entrepreneurial vision, leading her to participate in the EIT Climate-KIC business incubation program.
"I saw aquaponics as this perfect closed-loop system," she said. "But what really excited me was the potential to apply systems thinking to food production in ways traditional agriculture wasn't exploring."
After establishing GrowUp Urban Farms in 2013, her cross-domain expertise quickly earned recognition—she won the EIT Change Award that same year and was named a London leader in 2015.
From Box to Business: Critical Adaptations in Scaling
What happens when your revolutionary farming system demands more electricity than your business model can sustain? This question has collapsed countless vertical farming ventures, forcing Hofman to confront energy consumption as her next critical challenge.
The journey from shipping container to commercial farm revealed scaling challenges that required significant adaptation. The GrowUp Box served as a demonstration site to test market viability and build a business model. By 2014, the company had established Unit 84, the UK's first commercial-scale vertical farm.
But the most critical adaptation came when Hofman made a counterintuitive decision—abandoning the aquaponics system that had initially inspired her. The pivot wasn't just technical—it represented a fundamental shift in how she understood commercial viability versus elegant solutions.
"We realized that while aquaponics works beautifully at small scale, controlled environment hydroponics was more efficient for large-scale production," Hofman said. "The smaller the system, the harder to control. Larger aquaponics systems are actually easier to manage because larger water bodies are more stable."
This pivot allowed GrowUp to optimize space utilization and improve financial sustainability. It's a lesson many vertical farming scientists struggle to accept—sometimes the elegant solution that works in the lab isn't the most practical at commercial scale.
Energy consumption presented another critical challenge. GrowUp addressed this by partnering with a nearby bioenergy plant to source 100% renewable energy. This arrangement reduced electricity consumption by 40% compared to grid-connected vertical farms—a crucial advantage when energy costs threaten to sink vertical farming operations.
Water management provided another competitive advantage. GrowUp's recirculation systems achieve 94% water savings compared to traditional farming methods. The company also collaborated with Salinity Solutions to trial energy-efficient water treatment technology that recycles wastewater.
These adaptations weren't just technical tweaks—they reflected Hofman's fundamental insight that farms are communities of interconnected systems, not just growing technologies in isolation.
Breaking the Retail Barrier
While many vertical farms focus on growing the perfect product, Hofman recognized that retail success requires understanding what supermarkets actually need. How do you convince major retailers to stock products from a farming method most consumers have never heard of?
GrowUp became the first UK vertical farm to supply branded bagged salad to major supermarkets, including Tesco, Iceland, and Spar. But this breakthrough came from solving a problem retailers didn't even know they had.
"We designed our growing systems with retail requirements in mind from day one," Hofman explained. "It wasn't just about growing beautiful produce—it was about creating products that solved real problems for retailers and consumers."
The company's Unbeleafable and Fresh Leaf Co. brands addressed a critical retail challenge—short shelf life. GrowUp's products last 16 days, compared to the market average of 5 days. This extended freshness reduces waste throughout the supply chain and gives retailers more flexibility.
For convenience stores like Spar, this innovation transformed their fresh produce offerings. Simon Mitchell, Spar UK trading director, noted: "We are delighted to partner with Fresh Leaf Co. to offer our shoppers an affordable, longer-lasting fresh and healthy salad." The extended shelf life allows convenience stores to offer fresh options year-round, addressing traditional challenges of short shelf life in prepared salads.
The products are grown without pesticides and chlorine washing, contributing to better taste while extending shelf life. This combination of quality and practicality has driven nearly 800% sales growth year over year, with products now available in over 400 Spar stores across the UK.
The extended shelf life has transformed how retailers can offer fresh produce. As noted in GrowUp's retail partnerships, the longer-lasting salads allow convenience stores to offer fresh options year-round, addressing traditional challenges of short shelf life in prepared salads.
Measuring What Matters
For Hofman, success means measuring impact beyond standard agricultural metrics. What does it actually mean when a farm saves millions of liters of water or reduces transport emissions? GrowUp has achieved B Corp certification with an overall B Impact Score of 104.7, significantly exceeding the 80-point threshold.
"B Corp certification gives us a framework to measure what matters," Hofman explained. "It's not just about how much we grow—it's about how we grow it and the impact we have on people and planet."
The farm's operations aim to save 370 million liters of water annually and reduce transport emissions by 2.8 million miles. The company reduces supply chain waste by over 70% compared to traditional methods, translating to 4,000 tonnes of food waste prevented annually.
This commitment to holistic measurement has attracted significant investment. GrowUp has raised over £100 million since its inception, including a £38 million investment from Generate Capital in 2022 to expand operations in Kent.
Scott Jacobs, CEO of Generate Capital, described GrowUp as "one of the UK's most exciting and innovative vertical farming operations." This investment supports the Unbeleafable and Fresh Leaf Co. brands and enhances research and development at the Leaf Lab in Cambridge.
The company has also been recognized as one of The Sunday Times Best Places to Work for two consecutive years, demonstrating that its systems approach extends to human resources as well.
Cross-Pollinating Expertise
In August 2025, Hofman announced her departure from GrowUp Farms after 11 transformative years. As she transitions leadership to Will Howard and Mike Hedges, her journey offers valuable lessons for vertical farming scientists seeking to create commercially viable operations.
First, apply systems thinking to farm design. Hofman's IBM experience taught her to consider all stakeholders and optimize the entire operation, not just growing technology.
Second, be willing to pivot from initial concepts when scaling. GrowUp's transition from aquaponics to hydroponics demonstrates that commercial success sometimes requires abandoning elegant but impractical solutions.
Third, design with retail requirements in mind from the start. GrowUp's focus on extended shelf life addressed a critical retail pain point, creating products supermarkets actually wanted.
Finally, measure both financial and environmental returns. GrowUp's B Corp certification and comprehensive impact metrics demonstrate that vertical farming can balance commercial and environmental goals.
As climate disruption continues to threaten traditional agriculture, vertical farming offers a resilient alternative. But technical innovation alone isn't enough. Hofman's journey shows that successful vertical farming requires cross-pollinating expertise from business, environmental science, and agriculture.
"The future of farming isn't just about new technology," Hofman reflected. "It's about bringing diverse perspectives together to create systems that work for people, planet, and profit."
For scientists working in vertical farming research, that might be the most valuable insight of all.
Things to follow up on...
-
LED lighting innovations: GrowUp Farms employs tailored light recipes using Philips Horticulture LED lighting, which enhances product quality while consuming 85% less energy than traditional methods.
-
New leadership transition: Will Howard, formerly MD at Ella's Kitchen, has taken over commercial leadership while Mike Hedges was appointed as CEO to accelerate growth following significant investments and expanded retail partnerships.
-
Brownfield site transformation: GrowUp's Pepperness facility demonstrates how vertical farming can convert a five-acre brownfield site into the equivalent of 1,000 acres of grade one farmland, showcasing land use efficiency potential.
-
Water treatment collaboration: The company is working with Salinity Solutions to trial energy-efficient water treatment technology that recycles wastewater, potentially improving sustainability metrics even further.