3 Tips for Better Canopy Management

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Get a leg up on the competition with these pointers for maximizing yield.

May 2, 2018

Photo by Mel Frank

If the past few months have been any indication, cannabis prices are dropping fast, and they don’t appear to be rising anytime soon. In Oregon, for example, the overwhelming influx of farmers into the recreational market has created an unprecedented supply surplus, bringing prices to an all-time low. This “price correction” is unsavory news for business owners and their investors who have created their business plans based upon bygone pricing models. To make matters worse, the decline in cannabis pricing has been accompanied by a simultaneous rise in production and administrative costs, including electricity, nutrients, testing, permitting and more. In order to remain competitive, producers are faced with the challenge of finding ways to decrease spending while increasing production.

One possible approach to this challenge is the employment of effective canopy-management techniques. Executed correctly, these techniques will maximize the efficiency of your grow space without sacrificing the quality of your finished product. Proper implementation will lead to a reduction in labor and increased output, offering you a competitive advantage that will help you remain profitable in this rapidly growing and increasingly competitive industry. Since most grows are licensed by canopy area, accomplishing maximum output from each available square foot of growing space is of the utmost importance.

What Is Canopy Management?

Canopy management is the collective term for the sum of techniques and considerations designed to maximize the efficiency of your grow space. A well-managed canopy will consist of properly trained and pruned plants that are uniformly spaced and positioned in a manner that makes each one easily accessible. Successful canopy management can reduce the amount of time spent per plant and lead to increases in yield not previously thought possible. Here are the most significant aspects of proper management: knowing your strains, training your plants, and maintaining the canopy during the flower cycle.

1. Know Your Strains

The first consideration of canopy management is strain selection. It is crucial that you begin with a strain with which you are well acquainted. Don’t fill a room with an untested, unverified plant in hopes of keeping up with trends, and make sure to do at least one test run with every new strain to learn the plant’s characteristics and make note of its growing patterns and finishing time. This is by no means a waste of time; the knowledge and familiarity that you acquire during this process will more than make up for any perceived time loss.

Ideally, you will have only one strain at a time present in each flowering area. You need them to finish or ripen at the same time to complete harvest and cycle in another crop. Leaving a grow space half-empty while waiting for the rest of the crop to finish is very costly because it leads to more downtime than necessary.

Furthermore, when plants approach maturity, they begin to emit ethylene gas that accelerates the ripening of other plants around them—which can prevent strains with later finishing times from reaching their full potential. Mismatched strains can thwart your best efforts at maintaining a uniform canopy. The most common problem arises among plants with variable growth patterns, causing larger plants to tower over and shade out the smaller ones. If you must have more than one strain flowering in the same grow space, make sure they share the same nutrient needs, growth patterns and finishing times. This is precisely the kind of knowledge one acquires through a practical familiarity with the strains before beginning large-scale production.

SCROG netting utilized in the flowering stage
Photo by J. Amado Photography

2. Train Your Plants

Before you can expect to interfere with the plant’s natural inclinations, you need to understand how and why cannabis plants behave like they do. Fortunately, this is fairly straightforward. A female cannabis plant’s goal in life is to get pollinated, become fertilized and produce seeds that will sow new generations. Cannabis plants are acutely aware of their surroundings and of themselves in relation to these surroundings. As they begin to grow, they can identify their highest elevated branch and send the most growth hormones to it, ensuring that it remains the most prominent.

In nature, this awareness is crucial to the plant’s reproduction. As a general rule, the tallest budding plants will receive the greatest share of wind-borne pollen, allowing them to become fertilized, thus fulfilling their life’s purpose. Without training, a standard cannabis plant will grow one large cola at the top and several smaller branches below. However, by preventing the plant from giving preference to a certain branch, therefore preventing one to grow higher than the others, it will be “tricked” into sending an equal amount of growth hormone to each branch. This leads to the creation of multiple uniform colas that produce the most desirable flower, drastically increasing yield and eliminating the less-desirable, underdeveloped smaller flowers that would have otherwise sapped energy from the more desirable buds.

The training process begins in the vegetative cycle with the “topping” of the newly transplanted clones. Topping the plant will promote the growth of the lower branches that will make up the main structure of the plant. Early-stage topping will slow the vertical growth of the plant’s main stalk, resulting in a shorter, thicker and stronger stalk, that will be more structurally sound and better prepared to support a heavy yield.

To achieve the desired result from topping, first remove the top of the plant directly above the sixth node (branch site), leaving six remaining branch sites. Next, remove the two lowest branches. This will create a more workable space between the foliage and growing medium and will enable better airflow below the canopy. The remaining nodes will soon grow into the four main branches and will become the focus of the training.

The secondary branches are those that grow out of the main branches. These need to be treated just like the main branches, never allowing one to grow higher than another. You can achieve this with the use of training wires and also by gently bending the branches down by hand. As you bend down the secondary branches, they will begin to fill in the void spaces between the four main branches.

Once the secondary branches are well established (3 to 4 inches long) and level with each other, as well as with the tips of the main branches (like little Bonsai trees), they will be ready to be transferred into the flowering cycle.

3. Maximize the Flower Cycle

The SCROG method is a canopy management technique that can be deployed once the plants enter the flowering cycle. SCROG stands for “screen of green” and refers to the trellis or “SCROG netting” that is used. It’s a multi-functional tool that allows you to evenly position all the branches in the canopy while also offering support for the branches and developing flowers. Additionally, it acts as a grid that will show you where to direct the growth in order to achieve a full canopy without any void spaces.

Once introduced into the 12/12 photoperiod (12 hours of light/12 hours of darkness) of the flowering cycle, most plants will hit a structural growth spurt and double to triple in size over the following three weeks. During this period, it is necessary to remove any unwanted growth as soon as it appears, as doing so will direct the plant to delegate that energy to the more valuable branches. We understand “unwanted growth” to be any branch or node that has no chance of catching up to the others. Eliminating unwanted growth will not only promote more beneficial growth in other parts of the plant, it will also tremendously reduce the amount of time required for trimming, thereby reducing labor and, ultimately, the cost of production.

Using a SCROG net will require the plants to be arranged in rows. Each plant must be allowed at least 4 square feet of space or, in other words, 16 spaces on a typical 8-foot by 36-foot grid. Once the plants are correctly aligned and spaced, the netting can be applied directly above them. As the plants grow taller, the SCROG netting will be used to maintain the level canopy by allowing you to weave the branches through the different openings as you direct them to fill each space. Once the grid is filled, another layer of netting is installed over the first. The second netting serves to evenly distribute the branches and hold them upright, preventing them from collapsing under their own weight. The goal is to get as many branches to grow into each opening of the grid as possible without leaving any of them empty.

Manipulating the plants in this fashion allows you to intentionally direct growth to specific branches to create the perfect specimens for your grow space, which is the primary goal of canopy management. You must be able to artfully conceptualize what the finished plant will look like and then sculpt it over time. In my opinion, the ability to do this on a large scale, repeatedly and consistently, is a requisite skill for being considered a master grower. Employing the techniques mentioned above will undoubtedly increase your yields and reduce your overall cost of production, giving you a competitive advantage.

Dru WEst is a cannabis cultivation consultant and author of “Secrets of the West Coast Masters: Uncover the Ultimate Techniques for Growing Medical Marijuana.”