Many plants on Earth benefit from being pruned from time to time. The cannabis plant is certainly one of those plants. Properly pruning cannabis plants can help the plant reach its full potential by increasing the yield and quality of harvests. Improper pruning or too much pruning can be detrimental to a cannabis plant, and in some cases, can even kill the cannabis plant.
What are the major benefits of pruning marijuana plants? When does a cannabis cultivator know that it is time to start pruning your plants? What are the best pruning methods if pruning is appropriate? What are some common pitfalls when it comes to cannabis pruning? We will explore each of those questions in detail below.
Why Prune Cannabis Plants?
The two most important reasons for pruning cannabis plants are to increase airflow and increase light transparency. Some cannabis strains are notorious for producing an abundance of huge fan leaves, while other cannabis strains may not produce as many leaves. Fan leaves typically do not have trichomes on them, whereas sugar leaves are heavily coated with trichomes.
For strains that do not produce a lot of fan leaves, pruning branches and leaves will not be as important. However, for strains that produce a lot of leaf growth, pruning is a must to keep the plant healthy and happy. If a cannabis plant has too many fan leaves, essentially laying on top of each other, airflow is impeded and moisture can be locked inside the inner region of the plant, creating a breeding ground for various plant diseases such as powdery mildew.
Light transparency is really important for a cannabis plant’s growth. Not only do the inner and lower parts of the plant need access to direct light to ensure uniform growth, light can also help cannabis plants fight off disease. Most importantly, light transparency increases the number of buds on a cannabis plant and makes the bud sites more uniform in size.
Sometimes cannabis pruning is needed because of garden space issues. If you grow cannabis in a confined space, leaves can become pressed up against walls, creating the same issues as leaves laying on top of each other. For growers who are trying to be discreet, plants may need to be a certain size so that they don’t draw unwanted attention. In those situations, ongoing pruning may be necessary as the plant grows.
When To Prune Cannabis Plants
Knowing when to prune your plants is very important. Cannabis cultivators should avoid pruning cannabis plants leading up to the flower stage and definitely during the flowering stage. The best time to prune cannabis plants is early in the cultivation process, preferably in the first week or two of the vegetative growth stage.
A cannabis plant starts to produce leaves throughout the vegetative stage, however, it stops producing new leaves once the plant goes into the flower stage. Fan leaves will get larger, however, they will not regenerate. Any leaf that is cut off during the flower stage will not come back, so always keep that in mind. Once it’s gone, it’s gone.
As legendary cultivation expert Kyle Kushman points out, fan leaves are like the solar collectors for the cannabis plant, so cultivators want to be very mindful when removing them. Fan leaves play a big role in collecting sunlight for the photosynthesis process. They also directly contribute to the size and overall health of the cannabis plant. The only time that leaves should be removed in the flower phase is if the leaf is showing signs of disease or pest infestation, or if it’s required due to space limitations.
How To Prune A Cannabis Plant
The best approach to pruning a cannabis plant is a strategy that Kyle Kushman describes as “selective leaf pruning.” The ultimate goal when it comes to pruning is to increase light transparency toward the middle of the cannabis plant and airflow throughout the plant. With that in mind, start the pruning process toward the middle of the plant.
Watch air from a fan or wind go across the plant to identify areas where big clumps of leaves are catching the moving air. If the leaves are moving in a similar fashion to the sail on a boat, then some of the fan leaves probably need to be removed in order to increase airflow to areas that are most susceptible to moisture-related issues.
Also, removing the lowest branches helps fight off pests that might reside in the grow medium being used. The lowest branches typically do not yield desirable cannabis, and removing them helps the plant focus its energy on the upper branches, where the bulk of the quality flowers are produced.
Big fan leaves that are pointing toward the middle of the plant should also be removed to boost light transparency. You want to be mindful of future growth, and ultimately, you want to have branches growing laterally versus horizontally to ensure that as much of the plant as possible is getting direct light. If you combine proper pruning techniques with strategic bracing of branches, the end result is a plant that is wide and packed with buds. Be careful when bracing — branches break, and when they break, they usually die.
Cannabis Pruning Tips & Common Mistakes
It takes time and practice to become a master cannabis plant pruner. Novice cannabis cultivators will likely commit a mistake or two that they will hopefully learn from. The most common mistake of pruning a cannabis plant during the flower phase was already covered, however, there are other common mistakes that should be avoided.
Arguably the most common mistake that newbie cannabis cultivators make is stripping too many of the fan leaves from the plant. Cultivators should not prune more than 1/3 of the fan leaves on a cannabis plant in any given pruning session. Also, pruning sessions should be limited. Ideally, cultivators should only have to do bulk pruning once or twice on a cannabis plant.
Pruning limitations should not be confused with picking off dead leaves here and there. Always remove the leaves that are dead or showing signs of disease and/or pest infestation. If you have already stripped a cannabis plant too aggressively, yet it’s still in the vegetative stage, you can help address the issue by letting the plant remain in the vegetative stage longer than originally planned. Obviously, that is not something that is an option for everyone and it is situation dependent.