There's a classic Simpsons bit in 'Treehouse of Horrors VI' when Homer steps into an alternate universe where he discovers that the theoretical 'third dimension' is real.  Seeing the world in all three directions predictably befuddles him, and hilarity ensues.     

However, even in this strange 3-D realm Homer would feel right at home had he happened upon one of today's great monuments to a 2-D world:  the mega-indoor cultivation facility.  In here, it seems that the idea of exploiting an entire volume of space to drive down production costs is no match for the my-square-footage-is-bigger objective of sprawling, resource-hungry cannabis cathedrals.    

Monuments to ego aside, cannabis cultivation is a cold and heartless numbers game.  No matter how big or small your operation, those that can produce more for less will win.  It's time we re-imagine how indoor cultivation can remain cost-competitive; maybe it's time to GROW UP and consider the merits of vertical cultivation.

Growing plants vertically provides a solution with potentially several fundamental advantages for cultivators.  For instance, given the same footprint it offers increased plant yields and revenue generation, while decreasing energy/water consumption by several factors, over traditional horizontal cultivation.  [Vertical cultivation often uses gravity-fed hydroponic systems but can be modified for soil.] 

To be clear, the term 'vertical cultivation' in this context does NOT mean stacking horizontal grow trays on top of each other, with the plant canopy growing towards (perpendicular) the lights. Instead, imagine taking a horizontal grow and flipping it, along with its light source, 90 degrees so that the plants grow upward and parallel to the light. 

The concept of vertical cultivation may not be an easy one to visualize, so a simple analogy would be the difference between a book on a table vs. one in a bookshelf.  If you consider the book’s cover its ‘canopy’ then it looks like horizontal growing when lying flat, but vertical cultivation when standing up.  Although it may seem like a small difference in orientation, the effect of cultivating in three dimensions on overall cost efficiency is profound.          

Setting aside the mechanics of vertical growing for now, consider how true vertical growing impacts the numbers for a hypothetical indoor grow space that measures 12 ft (L) x 12 ft (W) x 12 ft (H):

Let’s start with the basics:

– Total area (ft²):  144

– Total volume (ft³):  1,728

Now, let’s look at a traditional horizontal grow within that footprint using 1000W high-pressure sodium lights that each cover 4×4 ft of canopy, operating at peak production (i.e. 3 lbs./light):

Let’s see what the numbers look like if you were to exploit the entire volume of space with vertical cultivation, using the scenario above as our baseline comparison. 

First, we take the existing grow (i.e. the ‘book’ lying down) and stand it up.  Simply by doing that you can now grow canopies on both sides (think of the book’s front and back covers).  Instantly, we’ve doubled our original capacity and we’re just getting started! 

Next, we face LED lights (of similar PAR intensity as HPS) parallel to the canopy and then do the same on the other side, as if two flashlights were pointed at the front and back covers of a book on a shelf.  Why LED over HPS?  Primarily because LED allows the canopy to grow closer to the light without damaging the plants, and does so for less operating costs.

Now, assume three feet spacing from one light to the other, with the canopies in between.  Then, take the entire configuration and repeat it four times to fill up the space.

Let’s see the results if the vertical cultivation output is only 2.5 lbs./light:

Note:  In neither analysis have I accounted for ‘empty’ spaces, like aisles, that are required for cultivation but do not generate revenue.

Taken at face value, the production and efficiency advantages of vertical cultivation over horizontal growing are clear, even if LED produces less yield/light.  The great news is, the theory has been put to practice and the real-world results hew closely to the hypothetical situation above.    

In fairness, adopting LED technology currently requires substantially more capital investment than HPS.  But, on balance, the additional upfront costs of LED are far outweighed over time by their ability to drive down operating costs while increasing production efficiency. 

And what became of Homer’s 3-D odyssey?  At first, he was apprehensive in his new world – scared, even.  But, he quickly realized that he could gain insights, experiences, and benefits impossible in 2-D, and was finally able to embrace the mysterious z-axis.  Oh, and he also found an erotic cake shop.