LEDs will allow Buckeye Relief to grow plants on two levels while avoiding heat stress.
Photo by Brian Maciver

In about 25,000 square feet of indoor growing area outfitted with LED (light-emitting diode) lights, Buckeye Relief in Eastlake, Ohio, cultivates medical cannabis for dispensaries in the Buckeye State.

The operation installed vertical grow racks but currently cultivates on one level, as it aims to expand along with Ohio’s medical-only market, says Jeremy Shechter, the company’s director of cultivation. (Ohio’s program launched in January 2019.)

“As the Ohio market develops—which we expect it to within the next probably 10 to 15 months—we have all of the electricity and all of the ducting and all the irrigation channels,” Shechter says.

Arguably the No. 1 benefit of cultivating cannabis under LED lights is that plants can grow on two levels without the hazard of heat stress, he says. Already, on its single level, Buckeye Relief has cultivated crops that have touched the lights and not burned. “The ability to grow vertical is huge,” Shechter says.

In the interim, the facility follows these lighting practices to cultivate quality cannabis indoors.

1. Install lights with 0%-100% dimming capability.

Cultivators using LED lights must be able to dim the lights by any percentage when their plants are stressed or when they need to make a foliar or pesticide application, Shechter says. This allows them to provide optimal light levels without wasting energy.

Not all LED dimming is the same, Shechter adds, so cultivators must connect “source” equipment, which provides a signal that gets modulated, to “sink” equipment, which receives a signal. For example, they can connect a sink fixture to a source control.

2. Run the grow a little hot.

Buckeye Relief keeps its grow room at 79 to 80 degrees Fahrenheit, 3 degrees above its leaf temperature of 75 to 77 degrees Fahrenheit, Shechter says.

“Just a simple rule of thumb that we've found is that leaf temperatures tend to be lower in LED rooms compared to HID [high-intensity discharge]rooms,” he says. “The difference between the air temperature and the leaf temperature is greater in LED rooms because you don't have that radiation from the lights heating up the leaves.”

Temperature directly affects yield, but cultivators should also pay attention to leaf temperature so they can avoid condensation on leaves. “If the temperature of the leaf drops below the dew point of the room, then you can have condensation on the leaf, and that obviously opens the plant up to pathogens, fungal issues, stuff like that,” Shechter says.

3. Integrate all environmental controls on a single interface.

Some cultivators piecemeal their environmental controls, with a thermostat here and CO2 monitors there. “People really like to cut costs by not integrating all of their environmental controls together on a single interface,” Shechter says. “I think that's a mistake.”

Environmental controls affect each other, so cultivators should connect them, Shechter says. By doing this, they can graph their data and track it over time.

Patrick Williams is a senior editor for Cannabis Business Times and Cannabis Dispensary.