Member of the month – LettUs Grow

By combining backgrounds in engineering and biology, LettUs Grow provide innovative ways to help indoor farmers scale up their operations to compete with traditional agriculture. The novel technology builds on the successes of hydroponics and addresses many of the issues which have been holding back indoor farming.

A common misconception about plants is that they only “breathe” through their leaves, but part of the oxygen and CO2 they use is also absorbed through their roots. By suspending our plants’ roots in the nutrient dense mist rather than in water, we’ve overcome some of the problems faced by hydroponics. Because they’re not submerged, plants can respire optimally during their whole life cycle. Using this system, called aeroponics, we’ve seen up to a 70% increase in crop yields over hydroponics. As is often the way, aeroponic growing’s biggest strength can also be its greatest downfall. Most systems produce their mist by pushing nutrient-rich water through strips of nozzles. The small holes quickly become clogged with falling plant debris and a build-up of salts and nutrients – much like how limescale forms inside a kettle. LettUs Grow has developed a system without any nozzles, so there is nothing to clog and break. Alongside the patent-pending hardware, LettUs Grow has also developed an integrated farm management software system, called Ostara®, which reduces labour requirements, optimises conditions for plant growth and makes farmers’ lives easier.

LettUs Grow has proven 150% crop growth rate increase over hydroponics across a range of leafy green crops and herbs in crop trials. From a study with the University of Bristol, this step-change in biological efficiency massively lowers the carbon footprint of aeroponics compared to hydroponics. It was shown that growing using LettUs Grow technology emits 60-90% less CO2 equivalent than industry-standard hydroponics. The main reasons for this are resource and energy reduction.

Global shipping plays a large role, to meet “year-round” consumer demands. Using LettUs Grow technology farmers can grow year-round, hence reducing the need for global supply chains.

LettUs Grow gives the farmer a number of key benefits:

  • The world’s first fully modular aeroponic system, allowing farmers to expand their operations incrementally
  • Easy to clean and maintain, nozzle-free aeroponics
  • Fully automated control of beds and lighting through Ostara™
  • Fine-tuned, precision control of irrigation across a whole farm
  • Grow beds designed specifically for vertical farm operations
  • Continuous data collection and optimisation services provided
  • Designed with the ability to integrate into fully automated farm processes

One-third of global carbon emissions can be traced back to our food production processes. As a result of an increasing global population, emissions are increasing even further, and farmland is becoming scarce. It takes 1,000 years to generate just 3cm of topsoil, and at the current rate of degradation, all of the world’s topsoil could be gone in the next 60 years, leaving little space to feed the growing global population. Indoor farming offers a solution. It can take the pressure off of our dwindling resources and enable us to grow food more sustainably anywhere in the world – from cities to deserts, to the South Pole.



The LettUs Grow team is made up of a talented, passionate group of scientists and engineers. The team combines nearly 10 years in urban agriculture, with the technical and business expertise required to take LettUs Grow to market.

The founders are made up of: Charlie Guy, who is the managing director of LettUs Grow, continuously driving the business forward. He combines a personable management style with technical skills in product design and sustainable systems engineering that ensures a detailed understanding of the business’ technical development. He has a background in renewable energy consultancy, sustainable design, and systems design. Jack Farmer is the operational and scientific director, specialising in aeroponic plant growth. His expertise centres on the biological requirements from aeroponic systems and is supplemented by two years’ experience in enterprise consultancy. Ben Crowther is the technical director. A design engineer by training, with over two years’ experience at a global FTSE 100 engineering firm. He combines a blend of mathematical, design and software skills with an acute understanding of operational good practice gained from managing large R&D projects in the defence sector.


On working with Farm491

LettUs Grow heard about Farm491 through SETsquared. They are using the hub to engage with potential stakeholders throughout the agricultural supply chain.

Visit the LettUs Grow website here.