South Mountain MicroFARM is a 100% LED-lit, aquaponic leafy greens cultivator in Maryland. The 7,500 square foot greenhouse is situated on the Sellers family’s 22-acre Christmas tree farm. Two-thirds of the greenhouse contains media beds, hydroponic channels and vertical racks that grow a wide range of lettuces, herbs, and microgreens. The remaining one-third houses tanks of tilapia. For Levi Sellers, South Mountain’s Head Grower, building the greenhouse was a homecoming in multiple ways. Levi has lived many lives - he’s worked in a hydroponics supply shop, as a mountaineering guide, and an EMT. But he felt agriculture calling him back to the family farm.
Building an energy-efficient greenhouse
One of the biggest challenges to growing year-round in Maryland is the summer heat and humidity. As a result, the greenhouse was designed with the west-facing wall open for ventilation, so that the winds that blow from west to east can passively cool the greenhouse. Levi installed shade cloths to further soften the relentless heat and light of Maryland summers. Vertical fans help control humidity levels. The lower heat output of the LumiGrow fixtures made them the practical choice for Maryland’s climate.
“When it’s 80% humidity and 100 degrees outside, there’s not a thing you can do. If it’s a cloudy day, you still need to run your lights so that you don’t lose production," explains Levi, "If we were using HIDs, we’d just be increasing our heat more. It’s much harder to control. We really like that we’re able to run our lights on cloudy days and not worry so much about the heat.”
Choosing LumiGrow has also allowed South Mountain to save on upfront infrastructure costs. Installing HID fixtures would have required them to install an additional electrical service panel and purchase a larger backup generator. When the power goes out for extended periods of time during the summer, the lower power draw of the LumiGrow fixtures makes it possible to run both the fish tanks and the lights on the farm’s existing generators. South Mountain MicroFARM also received a 40% utility rebate for purchasing energy-efficient lights, which made the price competitive with HID.
For South Mountain, the benefits of choosing LEDs over HPS were clear. LumiGrow’s high standard of customer service made the choice a no-brainer.
“We looked at several of your competitors, but they weren’t offering the same spectrum adjustability and their customer service wasn’t as good as what I experienced with [our Account Manager] Mike," recalls Levi.
According to Levi, South Mountain’s heads of lettuce are a lot bigger and denser than their hydroponically grown competitors at the grocery store. South Mountain’s lettuce fills the package better, making them more attractive to the end-consumer.
“When I compare photos of our greens grown under LEDs to others' grown with the same aquaponics system who went with the manufacturer’s recommendation to use HID, our LED-grown lettuce looks so perfect and pristine that it almost looks fake,” says Levi.
Levi runs his fixtures year-round to maintain the specific DLI that produces the uniform, picture-perfect plants that consumers are looking for. He tries to maintain about 18 hours of light per day, so the energy savings from his LumiGrow fixtures make a big difference. DLI and photoperiod are both key factors in biomass generation - the higher the DLI, the more biomass produced per plant lifecycle.
Levi’s LumiGrow fixtures have had a huge impact on his lettuce crop - they reach harvest size in 40-50 days, shaving up to 33% off the crop production cycle. This allows Levi to fit in more turns. Levi has also had great results with his microgreens - his LumiGrow-lit trials were ready to harvest 2-3 days earlier than his unlit microgreens. The LumiGrow-lit trays also produced approximately 10% more material per tray.
Levi has also experimented with allowing the heads of lettuce to grow for the full 55-60 days. He found that the LumiGrow-lit lettuce was 40-60% heavier. Restaurants buy lettuce by the tote, so heavier heads of lettuce allow South Mountain to reach the tote weight that restaurants expect with fewer heads of lettuce. All of this means more revenue for South Mountain MicroFARM.
In addition to producing a better-looking, more marketable product, South Mountain MicroFARM uses 75% less energy than their friend’s similar-sized greenhouse.
A pink beacon of sustainability
Initially, Levi had some concerns about what the locals would think about the greenhouse’s vivid hue illuminating the side of the mountain. His fears were unfounded. While the locals often jokingly ask if the farm is having a rave without inviting them, the truth is that they love the pink glow. Their kids adore how it stands out at night and proudly use it as a landmark when telling their friends where they live.
“It acts as a form of advertisement for us, and it’s really sped up the word of mouth advertising about our business and what we’re doing,” says Levi, “We’ve built our brand around being very sustainable and eco-friendly. We focus on every detail, down to the fish feed to make sure it’s locally sourced and sustainably grown. And what better way to show people that than an uncommon glow of pink from our greenhouse? The pink glow means we’re doing something different.”