Headshot courtesy of Jennifer Martin

1) Use LED lights that cover the entire plant canopy evenly, at close range. Many LED lights have physical dimensions that are much narrower than a typical 4-foot by 4-foot grow-tray footprint. This means that they must have 12 inches to 24 inches of clearance above the plants to light the canopy evenly, corner to corner. In a vertical setup, that’s a lot of unnecessarily wasted space. The less space between each growth tier, the quicker it is to access each tier. Quicker and easier access means better plant care, and thus improved flower quantity and quality.

2) Beware of implementing more than two tiers when first beginning. When you have only two tiers, you can easily stay within local code compliance requirements when it comes to the structural stability of mobile racking systems, as well the rules for worker safety. Unless the tiers are very tightly packed, the line between a second and third tier is the line between ease and difficulty—both in terms of design and functionality. With two tiers of 4 feet to 5 feet each, and the lowest tier raised 1 foot off the ground, access to the second tier can be accomplished with a rolling ladder, whereas three tiers would require a scissor lift. Further, the stratification of temperatures with three tiers starts to require a much more advanced (and expensive) cooling and air movement design.

This vertical grow in San Jose, Calif., shows plenty of room between racks for easy access for plant inspection.
Bottom photo: Jack Hutch

3) Leave enough space between and around racks for plumbing, air movement and worker access. Growers and investors often want to pack plant rooms beyond what’s reasonable to maximize yields. But doing so could compromise the healthy functionality of the space, both for plants and workers. Remember that the grow trays in the racks will need to periodically be removed, cleaned and/or replaced. If the aisle space is too narrow, this process could be frustratingly inconvenient.

4) In the project’s early design phase, plan for how to manage wastewater. Each municipality is different when it comes to what nutrient waste can go down the drain. Floor drains are the most convenient and inexpensive method of discarding water, but some localities require the nutrient-rich water be treated before being discarded. This will require pumps and holding tanks for runoff. With vertical mobile racking systems, drainage collection is more complicated than with single-tier systems. Have an experienced local plumber involved in the site’s design process. Wastewater management is an often-overlooked, and potentially costly, aspect of indoor site design.

5) Choose strains that are suited for vertical growing. Using strains that produce short plants will avert the possibility of plants overgrowing the space available per tier. These strains should be flowered before they grow too tall during the vegetative growth stage, and should no more than double in height during the first three weeks of the flower period. Choose strains that are also disease resistant. Vertical farms are designed with the idea of maximizing total canopy, but when half of that canopy is above head level, careful-examination time may be reduced. This could increase the chance of unnoticed mold and mildew outbreaks.

Jennifer Martin is an award-winning cultivator who specializes in indoor vertical LED system designs.  www.marijuanapropagation.com