Nemo’s Garden: How To Grow Plants Underwater

Last updated on October 23rd, 2023 at 08:44 pm

Many farmers have a hard time coping with the climatic conditions. But not only farmers have a hard time, even on the balcony there are always problems with the plants. Usually it is too warm or too cold, it rains too rarely and pests have now also settled on the plants. Sergio Gamberini had a world-changing idea. Why don’t we just grow plants underwater?

The story of Nemo’s Garden

In the summer of 2012, Sergio Gamberini, founder of Ocean Reef Group dive equipment, was enjoying a beach vacation on the Italian Riviera. In between dives, he enjoyed resting on the beach and chatting with friends. One day, the conversation turned to his other passion: gardening.

Could it be possible to create the perfect growing conditions for basil?

Like most herbs, however, basil prefers sheltered, sunny locations with well-drained soil and a stable temperature.

Gamberini took one look at the sea and came up with an unusual idea: why not try growing basil underwater? In fact, it would have allowed Mr. Gamberini to combine two of his passions: Scuba diving and gardening. He made a few phone calls and, with the help of his Ocean Reef Group team, began experimenting by sinking transparent biospheres 20 meters below the sea surface and filling them with air. The unusual project is located off the coast of Noli, about 70 kilometers west of the Italian port city of Genoa.

Why underwater?

With the underwater farm, there is virtually no interaction with the marine environment and related ecosystems. The plants are protected underwater from pests and storms. The use of renewable energy, from the sun and seawater, makes Nemo’s Garden a self-sustaining system. The waters of the Mediterranean Sea are warm, temperatures vary little and there is just as much light.
The microclimate and thermal conditions in the biospheres are, like a conventional greenhouse. They are not only optimal for plant growth, but also do not require additional energy sources.

How to grow plants underwater?

The greenhouse underwater
The acrylic constructions underwater, which resemble large balloons, are not called greenhouses but biospheres. They hold about 2,000 gallons of air and float at varying depths between 15 and 36 feet below the surface of the water.

Each biosphere has a step grid where divers can stand for deployment. When a diver is in the biosphere, 1⁄2 of his or her body is out of the water

These biospheres resemble a greenhouse. However, the system developed does not require the power, temperature control tools, or LED lighting used in traditional greenhouse growing.

If you would like to take a closer look at the Biospheres Underwater, here is a great video about it.

How the plants are watered and fertilized

A 10-meter spiral pipe is installed in the dome, which houses 60 seedbeds lined with Grodan rockwool. Irrigation water and fertilizers are held in a tank in the lowest part of the spiral. When a water pump pushes water from the tank to the top of the spiral, it descends by gravity to the spiral, providing food and oxygen to the plants. A fan – powered by solar panels on the top of the control tower – creates an airflow on the leaves of the plants.

Inside the biospheres, water condenses on the inner walls and drips back to irrigate the plants, while the warm, nearly constant sea temperature between day and night creates ideal growing conditions

What soil is used underwater?

None, because greenhouse gardening Unterwasser is based mainly on hydroponics. Hydroponics is growing plants without soil in a controlled environment. As hydroponics we really only know planting with expanded clay, here it is different. Instead of soil or expanded clay, a nutrient-rich solution is used to provide the necessary water and minerals to the roots.

Want to learn more about hydroponics? We have a fascinating article on hydroponic plants for you here.

How Nemo’s Garden is monitored

Safety for people and the environment is very important to Ocean Reef Group. However, this required a lot of investment.

The tree of life

In the center of Nemo’s Garden stands the Tree of Life, a 3.6-meter-high, 3-meter-wide metal structure that weighs about half a ton. It symbolizes evolution and the pursuit of innovation and technological advancement. The Tree of Life also performs an important function in the garden, covering the cables that lead to each biosphere. Thus, the area can be monitored from above, with the help of cameras.

The sensors

Each biosphere is equipped with sensors for carbon dioxide, oxygen, humidity and lighting. External water temperature is checked in the shallower and deeper biospheres.

See the article Plant Sensors for many more high-tech developments and how they work.

Safety underwater

A gyroscope checks the stability of each biosphere. It informs the surface that all anchors are working properly and registering any movement. There is a wireless underwater communication network with a range of 200 meters from the Tree of Life. When divers begin activity in the biosphere, they can communicate with each other and with the surface. Good communication is key when growing plants underwater.

What plants have been grown so far?

Gamberini has been experimenting with the biospheres and plants underwater for several years. They grow basil, lettuce, beans and even strawberries here.

You don’t have an ocean to plant in? No problem, we will easily show you how to grow strawberries on your balcony.

Can the project contribute to world nutrition?

Some researchers are still very critical of the Nemo Garden project. The costs are very high and unfortunately the whole system is very impractical. On land, mice, insects and other pests threaten to reduce the harvest, but these are not a problem in water. On the other hand, it is much easier to apply fertilizer on land.

Unfortunately, the plants do not get enough light underwater. They therefore remain somewhat smaller than those growing on land. About 40 percent of the sunlight sticks to the shell of the biosphere, so only a little more than half of the light reaches the plants. In addition, the sea does not retain the different wavelengths evenly. It “swallows” especially the red light, which the plants need to grow.

So growing plants underwater does not contribute to feeding the world. It is, however, an environmentally friendly and very exciting innovation, which may be explored further after intensive study.

If you want to limit your gardening skills to your apartment for now, we have some wonderful houseplants in our store. Feel free to drop by and get inspired.