This Hong Kong farm is using fish and blue lights to grow basil the size of your face

(CNN) Hong Kong has more skyscrapers than any other city, so it's not surprising that just 0.6% of its land is farmed. The city currently produces less than 2% of the fresh vegetables eaten there — but one agritech startup wants to change that.

In a 20,000-square-foot industrial warehouse in Hong Kong's Tai Po district, Farm66 grows plants on stacked shelves under LED lights. Protected from pests and pollution, this indoor farm uses no soil and minimal water says Gordon Tam, co-founder and CEO of Farm66. What's more, the controlled environment allows the company to direct the shape and size of the plants.

Making effective use of limited space, indoor farms in urban areas could help to reduce transport-related carbon emissions and improve food security in cities that rely on imports, says Tam — an issue that was thrust into the spotlight when supermarket shelves emptied during the pandemic.

So far, the company has raised more than $4 million in Series A funding, says Tam, with backers including the Alibaba Entrepreneurs Fund and startup accelerator ParticleX.

Now, Tam is looking to scale up production of his smart farming technology, as well as exploring ways to grow crops in extreme environments — including outer space.

A homegrown startup

Founded in 2013, Farm66 was an early pioneer in vertical farming.

In its patented aquaponics system, fish tanks are placed below shelves filled with leafy green herbs and vegetables. The plants filter water for the carp that live in the tanks, and the fish are fed leftovers — imperfect vegetables that can't be sold. Fish waste provides natural fertilizer for the plants, differentiating Farm 66's system from hydroponic systems, which typically use chemical fertilizers, says Tam.

Smart sensors monitor environmental conditions, including temperature and humidity, and the LEDs that illuminate the shelves use different light wavelengths to control plant growth.

"A blue light can increase the size of the leaf," says Tam. "The red (light) makes the leaf smaller, but the stem will be taller."

For some plants, like lettuce, a large leaf is desirable, whereas for tomatoes or strawberries, smaller leaves help direct more energy and nutrients into the fruit, says Tam. The company has experimented with different growing conditions to produce a variety of plant sizes — including a batch of basil with leaves so large they could cover a person's face.

A growing opportunity

Hong Kong's agriculture sector wasn't always so small, says Lam Hon-ming, a professor of life sciences at The Chinese University of Hong Kong.

In the 1960s, over 25% of Hong Kong's land was farmed for rice, fruit and vegetables, and until the 1970s, the territory produced around 50% of its own food, says Lam. But as the city grew, urban development displaced farmland, and low, seasonal income from farming further disincentivized local food production, he adds.

Indoor, vertical farms could solve these problems. By controlling the environment, farmers could grow plants more quickly and increase the number of harvests, says Lam.

He points to similar-sized cities with limited space such as Singapore — which produced 14% of its fresh vegetables in 2019 — to demonstrate what Hong Kong could do if it embraced vertical farming systems. Other startups in the city are also pursuing space-saving farming solutions: Grow Green, founded in 2016, has developed smart hydroponic planting systems for home gardeners, and Farmacy, founded in 2018, supplies refrigerator-like "mobile farms" to local shops and restaurants.

And while Hong Kong is short on space, it has a growing number of vacant industrial warehouses, with more than one million square meters unused in 2020, according to government reports. These warehouses would be "ideal" for vertical farms, says Lam.

From city limits to outer space

Farm66 is currently operating at less than 30% of its capacity, producing around two tons of vegetables a month, which it supplies to a handful of supermarkets and hotels, says Tam.

The high setup costs for indoor, vertical farms is still a barrier, he says, which makes turning a profit difficult. Tam declined to share the company's revenue but said that less than a third comes from vegetable sales. Instead, the company is shifting its focus to research and innovation, and is developing ways to make indoor farming more affordable.

The company has developed prototype robots to help automate tasks like harvesting and planting, which Tam says will enter mass production later this year. By establishing partnerships with factories in Mainland China to manufacture the robots at scale, Tam believes he can cut costs for future urban farmers.

Other Farm66 innovations include mini farms for homes, schools and businesses, which have sensors to monitor and automate plant care.

But Tam's boldest vision is a literal moonshot. He has designed the Future Green Tunnel, a conceptual rotating hydroponics system for zero-gravity environments, and is adapting indoor farming technology to grow plants in space.

Whether on Earth or in space, Tam hopes that indoor farming will flourish — and produce "high quality, safe vegetables for our next generation."