Coventry-based HydroGarden is finding its VydroFarm system - comprising a modular structure of mobile racks and gully trays that can be tailored to fit different spaces, crops and even climates - is attracting widespread interest since its launch just over a year ago.
"There is a lot of interest in urban and enclosed growing systems, even among old-school growers, some of whom are already seeing huge savings," according to business development manager Stephen Fry, who has 30 years of experience across commercial horticulture. "We are ahead of the curve in developing new systems for them."
The company has helped equip recent high-profile London urban agriculture ventures GrowUp, an aquaponics complex in a warehouse in Beckton; and Growing Underground, a subterranean hydroponic salad farm in Clapham, both of which "we have dealt with from day one", said Fry.
"We're now ready to take it to the next level and really test its export potential," he added, exhibiting later this year at the Global Forum for Innovations in Agriculture (GIFA) in Abu Dhabi and at GreenTech in Amsterdam.
The company has already equipped two farms in Singapore and one in Australia, growing micro-greens, herbs and salads. "We can supply that sector anywhere, having designed, tested and patented the equipment ourselves," said Fry, adding that in the process it has developed growing protocols for around 20 crops including strawberries, pak choi and even rhubarb.
Key to this has been its own experimental Project Urban Grow facility at its base in Coventry. This trial version of the VydroFarm system occupies just 24sq m but has a growing area of 55sq m thanks to its five-storey NFT hydroponic growing system on three mobile racks, which can produce nearly 2,000 lettuces in 28 days.
It uses Valoya LED lighting including the Finnish manufacturer's full-spectrum model. "If you compare it with a crop grown under 400/700nm red-blue lighting it's a better-looking crop and nicer to work in," said Fry.
Pre-mixed CO2 is introduced into the growing chamber via porous fabric "socks" for even distribution, he explained. "You can get a boost from a 140g crop to 170g just by raising the CO2 concentration to 1,200ppm. We introduce CO2 and light at different times, phasing in a 'dawn'
- you don't want to shock it awake at 3am. But it's a question of what crop likes what. We are playing around to get a better yield response."
Fertigating solution is first pumped through two filters. "The challenge has been to get equal pressure to each layer," said Fry, adding that as well as using 90 per cent less water than conventional growing "we don't waste the nutrients either - we can separate them back out".
Nutrient content, pH and conductivity are monitored and automatically compensated for, while sensors within the racks check light intensity, humidity and CO2 levels, all managed by MultiGrow software developed by New Zealand partner Autogrow Systems. Two CCTV cameras even provide a remotely accessible view of the crop. "It can be controlled from an iPhone. You can dial in from anywhere," said Fry.
Plugs are propagated and raised separately up to the 14-day stage, and are ready for harvest after four weeks in the chamber. "This is a more expensive environment so you only use it when you need it," he added.
Each gully can be individually removed and pressure-washed after the crop has been harvested, while lids of different hole spacings can be inserted for different crops. With a 28-day growing cycle and one-day washdown, 12 crops a year can be achieved. "That's for a 223g trimmed weight product," said Fry. "If you only need 170g, you can have 13 of those a year."
While the crop is not a commercial one, it is donated to feed the elephants at nearby Twycross Zoo. Fry estimates the cost at 20-22p per head, compared to 16-18p for a conventionally grown crop. "But for somewhere like Singapore, where everything is flown in and is two-to-seven days old, you can supply the varieties your customers want with a premium for freshness," he said.
During HW's visit, units were being prepared for shipping to Norway and Hong Kong. They are compact enough to fit into a standard 20ft (6m) shipping container. "The cost of electricity in Norway is low, making this attractive for cold, remote locations," Fry added.
HydroGarden will double the size of its testing facility by July and also plans its own range of LED lighting. It is hoping to receive for an Innovate UK grant with Nottingham University's Centre for Urban Agriculture to analyse the rooting and nutritional value of such crops.
"We know you can increase the oil content of basil or lower the potassium levels in lettuce for patients on dialysis," said Fry. "This sort of research is expensive. We have put in £350,000 of our own money to get to this stage, but we know we need additional help to prove the concept."
With a turnover of more than £20m, doubling since 2009, and around 80 year-round staff, HydroGarden has now "totally outgrown" its current premises, Fry added. Until now the company has largely been "under the radar", but it has raised its public profile with displays at the RHS Chelsea Flower Show, social media activity and a website that has already clocked up a million hits.
Fry admitted that some of its products for the home growing market "are a bit left-field for commercial production in huge volumes", but added: "If taken seriously this can make a big impact on food security and provenance. In future it could be built into blocks of flats or provide city dwellers with their own allotments. Why not have aquaponic allotments in old buildings? With our modular system you can move in and out in hours."