Lab is experimenting with hydroponics to sustain gardens in conditions where fresh produce only lasts up to 10 days into a three-month deployment

A navy research lab is working on a new project that could allow deployed sailors to finally grow fresh vegetables on submarines.

Engineering technician and 30-year navy veteran Don Holman is testing whether hydroponics can be used to sustain gardens on submarines at the army’s Natick Soldier Research Development and Engineering Center, located on the outskirts of Boston.

Fresh vegetables only last the first seven to 10 days of submarine deployment, which tend to be three months. After that, sailors have to resort to frozen fruit and vegetables.

Holman is currently testing growing vegetables in a 40-foot container at the research facility, using roughly seven-foot LED lights. The containers are kitted out with a central computer, that allows the researchers to control the temperature, humidity and CO2 concentration. Hydroponics allow for controlling the amount of nutrients in the water as well as the pH of the water.

He tested 83 vegetables in the first phase of testing and found that 51 of them were able to grow, such as different kinds of lettuce, kale and some root vegetables.

Others weren’t suited to the confined space and temperature, such as tomatoes, which required more heat, and cucumbers, which grew out of control and tangled around the lighting.

The $100,000 research project was born out of a hackathon at the Under Sea Warfare Center where sailors said they wanted salads to be served on submarines. Holman said providing fresh food will act as a morale booster and help the navy retain sailors.

“Sailors with good morale are productive sailors. It’s a win-win,” Holman said. “[The navy] is more aware of what the sailors’ concerns are, they’re addressing the quality of life issues to help retain them and make them more productive.”

The main hurdle facing Holman will be how to get the gardens onto submarines that have limited space. He is confident the current 40ft container model could be scaled down but submariners he’s spoken with have expressed doubt.

Retired navy captain Ronald Steed, a former sub skipper, told the Associated Press it would be a real challenge to fit a garden on a submarine, where space is extremely tight, “but if they could do it, that would be awesome”.

Steed expressed doubts over how much it could feed a crew of 170 on board a submarine for three months.

Testing on the hydroponic gardens will end in September and Holman will submit a technical report to the navy, who will decide if they wish to implement it on submarines.

It won’t be the first time vegetables are grown in inhospitable places. Last year, Nasa’s astronaut took the first bite of lettuce grown in space. It was grown at the International Space Station as part of a Nasa experiment using chambers of clay, fertilizer and water.