The Greenhouse Option

When the consumer thinks about the evolution of the cannabis industry, they think about it in terms of a growing movement. They may picture a patient treating their illness with cannabis oil, or students handing out pro-legalization flyers on a street corner, or the first day of a dispensary, with lines around the block. What they don’t picture is a greenhouse.

Yet, for cannabis cultivators, the evolution of the industry has brought a strong drive to cut costs. Whenever a state opens up a new cannabis market, a bunch of growers set out with the goal of raising a bumper crop, and then use the proceeds to expand their business. In these initial markets, the potential profits are so high that little thought is spared for overhead. Whatever cost you may encounter is usually justified if it increases yield.

Still, sooner or later, market forces come to bear. Prices go down, and the attention of the professional grower turns to efficiency measures. Many owners re-evaluate their operations after the initial rush, and start looking into whether there are areas where they can save money without any sacrifice to the quality of their crops.

Ken Vandevrede is the vice president of Terra tech, a vertically-integrated cannabusiness that includes growth, extraction and retail sales in Nevada and California. He talked with me a little bit about his company’s operations, beginning with how a greenhouse can use natural resources to full effect.

“The traditional way of cultivating cannabis is to grow it indoors, in warehouses. Our approach is to grow cannabis in environmentally controlled greenhouses,” he said. “That way you’re using the sunlight as your grow lights, and only using LED or HPS as supplemental lighting.”

Grow lights are usually where overhead reduction efforts start, as High Pressure Sodium (HPS) lamps are major power consumers. HPS lights are a type of High Intensity Discharge (HID) lamp, and tend to get used in grow operations because they have such a high light output.

That output comes with an equal cost in power, so many turn to Light Emitting Diodes (LED) as an alternative. LEDs need considerably less power than HID bulbs, produce less heat, and are more precise. There are pros and cons to each, but every lumen that the sun provides is one that they won’t have to make, and a greenhouse approach helps with that.

Of course, providing light is only half the battle. You need to keep a tight hold on the reins of your crop to keep them from entering the flowering or vegetative state prematurely. In an indoor grow, that’s as easy as dimming or shutting off the lights, but in a greenhouse that’s a bit more tricky.

“Overhead, there are energy curtains that act as shade curtains,” said Vandevrede. “If there’s too much light at any time, the curtains over the top of the plant close, to only allow a certain amount of light in.” If measuring and metering lumens with energy curtains sounds like the kind of delicate, exacting science that requires automation, that’s because it does.

“We automate the entire environmental control system,” he said. Irrigation, lighting, temperature, humidity, everything is controlled by a computer which is constantly taking readings and adjusting to achieve the desired conditions. The benefits of automation for growers is worth an article to itself, but it is beyond our scope here.

I asked Vandevrede whether ventilation was any less of a concern in a greenhouse than an indoor operation, and he allowed that it was just the same. “You have more tools at your disposal to deal with it, though,” he said. “The roof opens in certain places to let the heat escape. You can use a padded fan system too, which passes air past water to let the water cool the air.” There’s nothing stopping you from using air conditioning just like an indoor grow, either.

Greenhouses, indoor grows and outdoor grows are all viable options for cannabis cultivation. Most cultivators are well-versed in the plusses and minuses of indoor and outdoor approaches (more control vs more resource use, hermetic sealing vs the great outdoors, etc.) However, it may be that you find a greenhouse approach fits your climate, and your business plan, better than any other.

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