The legalization of cannabis in Canada last October created a new type of agricultural industry. Some estimate cannabis could be worth $6.5 billion in retail sales alone. That’s good news if you’re a grower.
But, as with any new industry, there’s a learning curve. And this one involves lights.
Growing cannabis is no easy task. The plants have different stages and require precise lighting cycles, with the largest area in greenhouses reserved for plants requiring 12 hours of sunlight and 12 hours of darkness. At one stage of growth, a plant might thrive best with 18 hours of light.
If the sun doesn’t provide adequate light, cultivators use artificial lights. These lights can be on at night, and the result — particularly for large greenhouse facilities — is a brightly lit night sky, commonly referred to as light pollution.
Nicole Mortillaro – CBC News – Jan 26, 2019.