Bumper crops: No soil required

“With the ability to control temperature and [organic] fertilizer direct to the roots of the plant we get higher yields, by faster turn over," said Mr. Wilda about the hydroponic growing process. — Photo by Rich Saltzberg

Vineyarders with any sort of green thumb are likely eyeing the progress of their tomatoes with no small amount of anticipation. Some gardeners, if they planted early enough, or employed good enough fertilization techniques, may be enjoying the first fruits off their vines already. But no matter one’s skill level, how much can one really expect to glean from a few vines in a garden plot? Five, maybe seven pounds of tomatoes per vine over the course of the season? Perhaps 10 or 15 with excellent fertilization?

Hard though it may be to believe, there happens to be a place on the Island where individual vines produce 60 pounds a week. Add to that, these are little cherry tomatoes. And subtract the use of any soil whatsoever. How is this possible? Not by wand or genie but by hydroponics. These tomatoes, which are completely organic from seed to fruit, are grown at Thimble Farm in Island Grown Initiative’s (IGI) vast greenhouse.

Rising from interconnected trays of pebbles, the tomato vines are each suspended by spooled string, which, somewhat counter intuitively, is not incrementally wound upwards but uncoiled, which in turn causes the expanded lower lengths of the vines themselves to coil in the tray, while the fertile tops continue to shoot up and bear fresh fruit. However, it isn’t just physical manipulation that’s responsible for such remarkable fecundity.

“We dose fertilizer [organic] that is made up of compounds the plants need to thrive six times a day,” said Keith Wilda, Thimble Farm’s manager, “and reuse the water after passing it through a filter system.”

In other parts of the greenhouse, sprawling aluminum table systems fed by piping and miniature canals, and also completely devoid of soil, nurture 2,300 individual leafy plants each. The table systems currently generate 110 pounds of greens apiece. In addition to finding their way into salad bags in the produce sections of the two Cronig’s markets and Alley’s Farm Stand, these greens are shipped weekly to local restaurants such as Lucky Hank’s and State Road where folks dining in or out can not only enjoy local produce, but more carbon-friendly produce as the delivery logistics do not include the extra fuel off-Island trucking and ferry passage incur.

Another advantage to the Thimble Farm hydroponic operation is year-round production.

“The grow cycle in the facility is five weeks from seed to harvest in the summer and six to seven weeks in the winter months,” Mr. Wilda said. “With the ability to control temperature and fertilizer direct to the roots of the plant we get higher yields, by faster turn over. Our 30,000 feet of grow space is about the same as eight acres on land propagation.”
“This is a real way to increase local food production year round, which also creates year round jobs,” said Sarah McKay, president of Island Grown Initiative “That is a way for IGI to share what we’re learning in this greenhouse so we can help others who are interested in hydroponics get started.”

Indeed, despite the great commercial promise of Thimble Farm’s hydroponics operation, its ultimate goal is fostering learning and seeding local earners.

“Here at IGI we are building and operating systems to first use as a teaching tool, for farmers and students to learn new techniques of growing local food year-round,” said Mr. Wilda. “Second, we are growing local food that is distributed to schools and local markets as part of the ‘grow local, buy local’ food system. Trying to show a model that allows communities like the Island ways to produce local foods year-round.”

Hitting it out of the park with garden produce has enabled Mr. Widla to now focus his energies on other types of food, notably his forte as the former head of the aquaculture program at the University of Massachusetts: fish. Rainbow trout are the first fish slated for farming. They will be sustained by an ingenious aquaculture system heavy with recycling components, components that will further nourish the already flourishing hydro-crops.

“The aquaculture system is a ‘recirculating aquaculture system.’ This basically means we remove solid waste [later used in compost for fields], use grey water to fertilize vining crops, water is further filtered through a biological filter [to reduce ammonia to nitrates], and nutrient enriched water is used to fertilize leafy crops like lettuce. This is a 24-hour loop, with the ability to run systems independently.”

If the amount of greens and tomatoes produced under Mr. Wilda’s auspices are any indicator, the availability of trout on the Island is headed for a pronounced and tasty upswing.

For more information about Thimble Farm, visit islandgrown.org.