Greenhouse Insider: Embracing Year-Round Production

Controlled Environment Agriculture (CEA) has been a phrase used quite a bit recently, especially by growers in the North looking for ways to produce year-round. Specifically, CEA is defined by Cornell University’s Biological and Environmental Engineering Department as “an advanced and intensive form of hydroponically-based agriculture. Plants are grown within a controlled environment so that horticultural practices can be optimized.”

According to Cornell University’s Louis Albright, a professor in the Department of Biological and Environmental Engineering, the biggest issue with CEA is energy. “Unless you have computer control of lights, it will be difficult to make this work economically,” he says. “The goal is to produce the same amount of light for consistent production, even in Ithaca, NY.”

In the last few years, he says interest has been growing in CEA because of the local food movement. “There is more ferment in the industry because of the locally grown movement, and I think CEA has a good chance of success,” he adds.

Living The Dream

Bolton Farms, a hydroponic greenhouse facility in Hilton, NY, was mentioned by Albright as one that is doing what it takes to achieve year-round production. The operation produces micro greens, lettuces, herbs, greens, chards, green beans, and heirloom tomatoes in a half-acre greenhouse.

Owner John Bolton says he opted to get involved in hydroponic production after the manufacturing company he worked for moved its business to Mexico. Bolton was involved in agriculture for years, or as he calls it, “casual farming.” This past winter the farm supplied three indoor markets and several restaurant wholesalers, and Bolton says he plans to sell his produce at eight markets in the summer.

Just how is Bolton able to produce in the dead of winter? Well, he has a plan — an energy plan. An energy plan entails figuring out how to heat your greenhouse yearly and not be subject to rising energy bills, he explains. “Right now if we were using oil heat, we’d be in trouble because the cost for oil is doubling.”

The operation uses wood boilers to heat 4.5 miles of radiant tubing in the concrete floor of the greenhouse. “The radiant heating from the floor is so efficient that we can afford to load our stoves,” he explains. “Even though there is work involved, it is very inexpensive fuel and it is renewable. This is the cornerstone of being able to grow in the winter months or even the fall in upstate New York.”

The facility also has hanging hydronic heaters that blow air throughout the greenhouse. For optimal production, Bolton says it is important to keep the temperature in the greenhouse consistent throughout. He also installed a retractable thermal insulation blanket and shade curtain to maintain temperatures during cold winter nights. The blankets have been critical to the winter growing success.

“There is only one degree difference from an outside wall to the inside of the greenhouse because the fans move air constantly throughout the greenhouse,” he explains. “To be efficient, the fans have to be at the right height and direction above the canopy.”

The other thing Bolton must pay attention to is artificial lighting. Some of the crops grown in the greenhouse, particularly basil, swiss chard, and herbs, need supplemental light in the winter. Bolton has determined that he needs the most artificial lighting three months of the year: November, December, and January. “What we have found is that come February, there is more sunlight and the days are starting to get longer, so the need for artificial light is reduced.”

All components of the greenhouse, says Bolton, are computer controlled. The computer senses light, heat, and humidity and the computer controls make decisions on when to open and close vents, turn on a heating zone, run water, etc., says Bolton. “It is truly a controlled environment,” he says.