How to Make the Most Efficient Use of Your Cannabis Production Space
July 8, 2021 
When it comes to controlled environment agriculture (CEA), every inch counts. The cost to build a facility that maintains year-round optimal growing conditions will far exceed the capital expense of any traditional farming method. Grow lights, recirculating fertigation systems, and climate control technology can push capital expenses into the seven-figure range. To ensure a rapid return on investment, CEA facilities must make efficient use of their production space.
With cannabis, that means scheduling dedicated areas for vegetative and flowering plant growth.
Separate Spaces Make Good Business Sense
Finished plant height and yield are directly influenced by the time a plant spends in the vegetative growth stage. This development period helps the plant establish a healthy root system and robust branching structure that can support the weight of its flowers later in the crop cycle.
But during this time, plants only require a fraction of the space they’ll need once they reach maturity. In vegetative growth, plants are much smaller, and they can be grown at a much higher density than mature flowering plants. They also prefer slightly higher humidity than flowering crops, and they require a different photoperiod.
For these reasons, vegetative and flowering growth production are incompatible with one another and need to occur at separate times.
As a result, cannabis cultivators must do one of two things: Either grow plants vegetatively first and then switch to flower production in the same space, or utilize separate vegetative and flowering growth areas. The latter option holds the most significant potential for production efficiency.
Focus on Turns Per Year
Since cannabis cultivators make money by selling flowers, the focus should not only be on yield but turns — or harvests — per year. The more turns, the more revenue a production facility will generate each year.
One of the best ways to encourage maximum turns is through a dedicated flowering space. As soon as a crop is harvested, the area is cleaned and re-filled with plants that have already completed their vegetative growth cycle and are ready to flower.
A grower using this technique could realize up to six harvests per year when cultivating varieties that flower in eight weeks. Otherwise, if plants are grown vegetatively for three weeks and then forced to flower in the same area, the grower could only realize four harvests per year. Not only would there be less revenue, but during the vegetative growth period, there would be a lot of underutilized space.
However, using separate growth areas can create some challenges.
- Increased labor. Plants must be physically transported from the vegetative growth area to the flowering room. Vegetative plants can reach 18 inches or taller, and they must be carefully moved to prevent inflicting damage. This process requires more time and labor than simply plopping down young seedlings in a production area and leaving them alone for 11 weeks.
- Timing is essential. If there is a delay anywhere in the program, it can result in a production bottleneck. If a flowering crop needs more time to finish, it means holding vegetative plants longer. Beyond a week, plants can become unwieldy and start growing into each other if there is no additional space. In extreme conditions, plants may need to be pruned to be kept under control, potentially affecting their performance in flower. Holding overgrown plants at a high density can also increase the chance of disease, insect, or pathogen problems.
- The transition can be rough. Moving plants from vegetative growth into flower can be stressful if they have not been properly acclimated. This is especially common with indoor growers. Vegetative plants grown at a high density under moderate light levels can experience shock when moved to a lower humidity environment with increased airflow and stronger lights. Stressed plants will wilt even if there is water in the substrate, and they’ll begin to turn yellow within 48 hours of the move.
These challenges shouldn’t keep growers from using dedicated vegetative and flowering growth areas. Follow these tips to help ensure a smooth transition:
- Establish an efficient transportation process. Mobile multi-tiered racks work well for moving plants indoors, and daisy-chained covered carts work well for moving high volumes of plants outdoors. In tight growing spaces, like floating aisles between rolling benches, growers can eliminate walking back-and-forth by establishing a human chain. It involves a lot of people pitching in, but only for a short duration. When people are strategically positioned, the plants can move from the grow bench to the transportation cart without anyone taking a step.
- Oversize your vegetative growth room for emergencies. Typically, 25% of production space is dedicated to vegetative plant production, but an increase of just 5% to 10% can provide a buffer if there’s a disruption in production. Multi-tier racks can help growers increase their production space without expanding the overall square footage of their facility.
- Ease into the move. Acclimate your plants by slowing easing them into the two most potentially shocking factors of any flower room: low humidity and high light intensity. Do this by treating the first two weeks of flower as if the crop was still in vegetative growth. At this stage, the plants are not ultra-susceptible to botrytis, so there is no risk in maintaining high humidity levels. After move-in, gradually drop humidity over the next 10 to 14 days.
Growers should take the same philosophy with lights. Match the light intensity of the flower room with that of the vegetative growth room, and then bump it up slightly every 24 to 48 hours. This can be done with lights that have dimmers, or if that’s not an option, start with lights hung high and slowly lower them. If they can’t be dimmed or lowered, manually shut off a third of the lights and gradually turn them on over the next ten days.
The plant production business is as much about efficiency as it is quality. Most cultivators strive to grow quality product, but it can put a strain on their bottom line if they can’t do so cost-effectively. Programming production with dedicated vegetative growth and flowering rooms will ensure that growers realize the maximum output from their limited cannabis production space.
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