The air of the greenhouse stands at 79 degrees with humidity hovering around 83 percent. That's a pretty good environment for a typical plant.

But this is no ordinary greenhouse: It's 20 feet under water, anchored to the floor of the sea just off the coast of Noli, Italy.

This is Nemo's Garden, an experimental project in its fourth year, operated as part of the family-run Ocean Reef Group.

The balloon-like biospheres take advantage of the sea's natural properties to grow plants. The underwater temperatures are constant, and the shape of the greenhouses allows for water to constantly evaporate and replenish the plants. What's more, the high amounts of carbon dioxide act like steroids for the plants, making them grow at very rapid rates.

Ocean Reef Group — a diving equipment company — is monitoring five balloon-like biospheres that house a number of plants, such as basil, lettuce, strawberries and beans. The group has a patent on the structure and plans to build a few more to experiment with other crops, such as mushrooms, which should thrive in the humid environment.

Sergio Gamberini, president of Ocean Reef Group, came up with the "crazy" idea of growing plants under the sea while on a summer vacation in Italy. He immediately made a few calls and started experimenting, sinking the transparent biospheres under the ocean and filling them with air.

"I try to do something that's a little different and to show the beauty of the ocean," Gamberini said. "I hope to do something for the young people and to inspire new dreams."

Two years — and many rough storms — later, the company had their fleet of biospheres anchored to the seafloor, complete with live Web streaming and sensors collecting data in real time on oxygen and carbon dioxide levels.

"It's been a learning curve," said Sergio's son, Luca Gamberini. "We completely lost the crops four times, but it didn't really matter because we have such great growth rates."

The company has boasted a decent crop output every year despite its challenges. Although they have not sold the produce yet, Sergio Gamberini's wife has used it to make pesto for large parties.

The hope is that the company's success so far may lay the foundation for a new form of crop production that can be done without harming the environment.

In fact, the biospheres are attracting wildlife. Octopuses seem to like taking shelter under the structures, and endangered seahorses have gathered beneath the biospheres to develop nurseries. Crabs have also been known to crawl up the anchors and into the greenhouses. So far, none of the animals have posed a threat to the plants.

Underwater biospheres in the Nemo's Garden project, off the cost of Italy, have attracted a number of marine animals, including octopuses and endangered seahorses. (Ocean Reef Group)

"It's so kind of sci-fi to see these two different forms of life interact," Luca Gamberini said.

Right now, the group is only able to set up their biospheres during four months of the year, from May to September, as allowed under a permit with the local government.

That may change in time, but at the moment, the project is providing information for a new area of underwater plant growth. As a small company, Ocean Reef Group isn't able to spend a lot of money on the research for the project, and Luca Gamberini said he relies on support from a number of partners to keep it going. The company is also planning to launch a crowdfunding campaign next week to support further development.

The company plans to roll out a much smaller aquarium version of the biospheres that people can experiment with in their own homes, with hopes that a broader use of the technology could lead to new insights.

But the plans don't stop there.

"In the future, it'll definitely be something that's economically sustainable," Luca Gamberini said. "I see possibilities for developing countries where harsh conditions make it difficult for plants to grow."

The company has already received some of interest from groups and countries wishing to expand on the concept, but so far they have declined selling their product.

"It's incredible the great excitement surrounding our project," Sergio Gamberini said. "We want to test first because we want a project that's professional. We want to do this in the right way."

Read More: