For purposes of practical management, I have always considered the canopy in cannabis grow facility to be essentially one giant, living, breathing entity. While each plant is independent of the other, the interplay between the individual plants has a considerable effect on the result of the group. Additionally, in large part, plants that within the same indoor room or greenhouse space also share the same environment, perhaps similar lighting, nutrient regiment, pest treatments, and grow medium.
The leafs produced within the cannabis canopy serve both as a source to generate energy from light, as well as as a means for the plant to absorb carbon dioxide and release oxygen. The structure of the plants serves to support the plants leafs and flowering sites. Gardeners have long pushed the cannabis plant to perform beyond what it would in nature, through selective breeding, the introduction to the indoor environment, and by contorting and training the plants to achieve ideal productivity by maximizing the size of the plant and its flower sites.
To begin with a strategy for optimal management of the canopy, let’s visualize it as three dimensional structure, a box if you will, with each plant’s branches serving like the steel beams in a skyscraper, adding support and additional flowering sites. Gardeners often poorly utilize the lower part of the plant, through neglect or overly aggressive “lollipopping,” which is the practice of cutting off lower branches with the intent to force more resources and energy to the top of the plant. As we consider the canopy as a three dimensional structure, maximizing the output of its cubic feet, with an emphasis on the often neglected lower area, is one of our main focuses.
A high production flowering canopy begins with proper vegetative growth, as robust vegetative plants will usually translate into a favorable flower output. I teach my staff to envision each plant fully flowered while they are still in the vegetative cycle, with the point being, how will the plant grow and produce in flower once it makes the transition. Is it big enough, both in stalk girth and vertical height, is it too stretched out, are there the correct about of primary nodes? After seeing many crops grown to fruition, one can anticipate how each plant will flower and make corrective adjustments to improve the plant and canopy structure before they make the transition.
Primary nodes are the main branches of the plant that become the impressive top colas that we all like to gawk over. While having a huge cola is a great conversation piece, it’s not necessarily practical to achieving maximum output and profitability (FYI, if once was cultivating using a true, sea of green approach, with 100 plant in a 20 sq. foot are, this would not apply). Most gardens grow medium to large size plants, unless it’s advantageous to use a sea of green, such as when using vertical farming technologies. Forty to eighty primary nodes per 20 square foot of flowering space is recommended, with the variance attributed to strain and plant count specific considerations.
Example- With a 3 x 3 (9) plant array under a single flowering light, on would attempt to have 4 to 8 primary nodes per plant, totaling 36 to 72 primary nodes.
36 to 72 primary nodes are typically the most productive amount in a 20 square foot area for maximum fdried weight flower output, which a single lighting unit would usually cover. In the next two articles, we’ll review plant contortion techniques in the vegetative stage, a well as canopy maximization strategies in flower.
By Ben Burkhardt