"Our greenhouse facility is about ten times the size as our previous indoor grow and costs roughly the same to operate." From full environmental control to supplemental lighting, automated drip irrigation, and under-bench heating systems. That is just some of the technology that Bask uses to achieve the best growing practices in their greenhouses in Massachusetts. Christian Powers is the Director of Cultivation at Bask and explains that the company started out growing indoors. "We moved from our indoor grow to our greenhouse facility back in February of 2020, following our own research into existing cannabis markets such as Washington and Colorado. We noticed that the prices were dropping consistently as markets started to mature and knew we needed to think forward about the longevity of our company." Moving to a greenhouse and utilizing natural resources like the sun, allowed Bask to provide the same quality of flower, while reducing operating costs, being more sustainable, and environmentally conscious.
Temperature and humidity control
In their six greenhouses, controlling the temperature and humidity works quite a bit differently now, compared to their previous indoor facility. "The main difference between an indoor grow and greenhouses, is that most greenhouses don't use traditional air conditioning or dehumidification," Christian explains. "When we need to vent our greenhouses, we pull the cooler outside air to get the temperatures down to an ideal range. In the summertime, when it can get up to anywhere between 80 to 100+ degrees Fahrenheit, we have evaporative cooling pads that we use to cool the greenhouses as needed." Regarding relative humidity, Christian explains that venting the rooms is the primary way to control it. "In our flowering greenhouses, when the humidity starts to rise around 60% or above, our exhaust fans will run periodically to exchange the humid air in the rooms with fresh air from outside." In their vegetative greenhouse, the company does utilize humidification systems to keep the RH at the ideal percentage for optimal plant growth year-round.
Now that the company is growing in a greenhouse and using outside air to vent, that does increase the risk for pests and pathogens. "Pest pressure can fluctuate throughout the year, with the summer months typically being the most challenging due to outside plants and flowers being in full bloom. However, we have IPM strategies in place to monitor any issues that may arise, including regular crop scouting, releasing beneficial insects, and preventive foliar applications."
Greenhouse CO2 and LED trial
Due to the nature of greenhouses venting and exhausting air throughout the day, the use of injecting CO2 in greenhouses has been widely debated amongst growers. In 2022, Bask successfully ran a CO2 trial with an elaborate setup of PVC manifolds and CO2 tubing running to every bench in the greenhouse. Injection times were programmed through their environmental controls to only inject CO2 while the rooms weren't exhausting. This allowed the plants to take up CO2 and prevent it from being instantly vented out. Bask quickly noticed increases in plant growth and vigor, as well as trichome production and overall yield.
Most recently, Bask is trialing new LED lights in their vegetative greenhouse as well as one of their flowering greenhouses. While they currently use HPS for their supplemental lighting, Bask is always looking for ways to maximize efficiency, saving on operating costs, and engaging in sustainable practices. They believe this will be crucial for their long-term, sustained success in the ever-changing Massachusetts cannabis market.