Hydroponically-grown tomatoes make their debut

The commute from California to Kaua‘i is a long one for produce that braves 3,000 miles of water to arrive unblemished in the chill section of markets island-wide. Picked green for shipping, most tomatoes in the grocery store haven’t been kissed by the sun in weeks. Here on Kaua‘i, the commute just got shorter for cherry and beefsteak tomatoes.

Still warm from the sun and with under 20 miles of road time, Kaua‘i Fresh Farms harvested Kaua‘i’s first commercial hydroponically grown tomatoes last month. Nutrient-infused water feeds these local beauties that possess both the sweetness and the firm texture reminiscent of a homegrown variety.

Beneath the canopy of a 144-foot by 96-foot greenhouse, row upon row of vine rise to a height of 8 or more feet with globes of bright fruit dangling from their surprisingly lean trunks.

Owner of this uncharacteristically sterile farm is Bill Porter who was compelled to grow tomatoes for one simple reason: “I wanted a tomato that tastes like a tomato,” said the North Shore resident.

Porter combed the nation’s top agricultural schools for an expert in hydroponics. He found Dr. Hyung Jun Kim, a researcher from North Carolina State University where Kim did his post-doctoral research on how to grow greenhouse tomatoes with the highest sugar content. Kim designed a complex hydroponics system for growing tomatoes in Kilauea.

A four-bay greenhouse provides temperature control, reduces evaporative water loss and is useful for disease and bug control. From a computer panel in the warehouse adjacent to the greenhouse, Kim feeds the tomatoes a nutrient solution through “intravenous” tubes that connect to a small square tub full of perlite. Perlite is a naturally occurring siliceous volcanic rock that is used as a medium. Perlite has excellent air to water holding abilities, provides drainage and supports the plant’s roots.

Kim can also exercise climate control. Kaua‘i’s tropical heat in summer is too much for tomatoes so the greenhouse is equipped with a cooling system. Along one side of the greenhouse are giant fans that bring air in. On the opposite wall is a “pad.” Cold water washes down the pad — so the air that flows over the pad keeps the temperature inside cooler. A pump circulates the water through the 18-inch pad. Ideally, the temperature hovers near 88 degrees Fahrenheit. The fans are turned off only at night when temperatures drop. On the outside of the greenhouse is a covered lean-to structure so that bugs do not get sucked into the system.

A carbon filter purifies water that is fed to the tomato plants and through EC (electrical conductivity) Kim is able to measure how much nutrition is in the water.

For eight months the plants will be in constant production. As the plant grows, dead leaves are stripped from the bottom and the lean trunk of the tomato plant will be strung gently toward the polycarbonate roof high over head. By the end of production, the tomato plant will be twenty feet tall.

“We keep it lean,” said Kim in a thick South Korean accent. “By trimming the suckers so it won’t turn into a bush.”

Fourteen years studying hydroponics both here and in his home country and Kim is an expert. The entire greenhouse and computer system were designed by him. Before moving to the United States he worked for the South Korean government doing hydroponics research.

Tomatoes are harvested on Mondays and Fridays and delivered the same day.

“We don’t pick the green,” said Kim emphatically. “We only pick the red.”

Want a vine-ripened

Kaua‘i tomato?

Banana Joe’s, Kilauea

Big Saves stores, all

Cost-U-Less, Kapa‘a

Foodland stores, all

Healthy Hut, Kilauea

Koloa Natural Foods

Kukuiula, Poi‘pu

Papayas both locations

Sueoka, Koloa


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