Cannabis owners and operators must weigh multiple factors when deciding what type of greenhouse is best for their cultivation plans and climate, including cost and materials used. Jacob Carson, systems engineer at Prospiant, explains the most important, foundational questions owners must answer when considering a greenhouse structure.

A greenhouse structure is a small portion of the total cost of a cultivation facility and may vary depending on size and complexity. Constructing several acres of hoop houses will cost as much as a small gutter connected sealed glass venlo. To be successful, you must first be honest about your budget and determine if you’re seeking to minimize cost or maximize yield.

A greenhouse can be built in less than a month; that’s often the easy part. The challenge is starting up the facility at the end of the buildout. Under a strict schedule, you can go from schematic design to commissioning in a year, but it’s not uncommon for the process to take several years. This is particularly true if there are hold ups with permits, utilities, groundwork, and design changes.

The greenhouse structure is made from steel and aluminum and can be engineered to meet typical or expected snow and wind loads. The greenhouse roof is covered in a transparent material such as glass, polycarbonate, acrylic, or poly films. Each roof material has its merits, but glass is considered the premium choice due to its light transmission and diffusion properties. The sidewalls of a greenhouse are typically polycarbonate or an insulated panel. It is common for the sidewalls to be opaque to allow for increased security and blackout.

Cannabis can be grown in a greenhouse all year; it is typical to get four to six harvests per year in a greenhouse. This is done using both supplemental lighting and blackout systems. In the summer, you’ll have lots of natural sunlight and lights may not need turned on, with blackout screens needing to be pulled to help provide a proper flowering photoperiod. This is different than in the winter months, when there may be fewer than 12 hours of sunlight and the lights will likely be on all day. 

The challenge of a greenhouse is that the weather not only changes seasonally but also day-to-day. In winter, you’ll need to heat the greenhouse and dehumidify with dry outdoor air. In summer, the shade screens are pulled and supplemental dehumidification is needed as the outside air may be too hot or too humid. To help manage these conditions, utilize intelligent environmental controls systems that can provide sensor measurements and adjust equipment accordingly. 

Cannabis Business Times’ interactive legislative map is another tool to help cultivators quickly navigate state cannabis laws and find news relevant to their markets. View More