In the cannabis industry and especially among cannabis growers, defoliation continues to be a divisive topic. Many people still believe that defoliation isn’t necessary for a growing cannabis plant. Those that acknowledge its importance are also still likely to disagree on what defoliation method works best and which doesn’t work at all.
But ultimately, defoliation is good for cannabis plants and there is enough scientific research to prove it. It’s important to note that defoliation is only beneficial to the plant when done right. This simple guide helps cannabis growers learn more about defoliation techniques, plus the specific benefits plants derive from being defoliated every once in a while.
What is defoliation?
Defoliation is simply the act of cutting leaves off a cannabis plant for the purpose of pruning. It is backed by scientific research that shows that older plant leaves do not contribute as much to plant growth as new, smaller leaves, but instead, they become detrimental.
According to research, as plants grow, so does the size of their leaves. Older leaves become larger, thereby taking up even more water, sunlight and other nutrients even though their ability to support photosynthesis and other necessary processes is more limited. Defoliation aims to eliminate these older leaves and rejuvenate the cannabis plant.
The benefits of proper defoliation
When done right, defoliation triggers a long list of benefits for the cannabis plant. Some of them include:
Larger yields
Defoliation has been proven to boost the yields you can get from your cannabis garden. There are two angles to this: the first revolves around the plant hormone ethylene, which is known to lower yields because of its ability to trigger aging processes within plant cells.
Per nature’s design, ethylene is found in higher concentrations in older leaves and flowers, such as those at the lower ends of the cannabis plant. Defoliation effectively nips these leaves and flowers, triggering higher yields for the plant.
The second angle revolves around defoliation’s ability to increase the exposure of leaves to sunlight and air, which directly stimulates more photosynthesis, better growth and larger yields by harvest time.
Efficient light absorption
Plant leaves and flowers need direct light for a number of reasons, but mainly photosynthesis, faster growth and formation of resins. Defoliation helps clear overgrown sections of the plant by eliminating unnecessary leaves and exposing others to light.
When choosing leaves to spare, experts recommend that you give priority to newer, younger leaves because older, larger leaves (usually located lower down the plant) carry out less and less photosynthesis regardless of the amount of light received.
Note: If the cannabis plants are so close together in a small garden, you might need to nip a lot more leaves per plant for them to access any light. Just don’t overdo it because too much leaf loss directly affects plant growth.
Better ventilation
For cannabis plants, increased growth also means more leaves everywhere. When no defoliation is done for a long time, the lower and inner sections of the plant see their air circulation cut off by the many leaves around foliage, which is detrimental for growth as there is limited gas exchange via the stomata in the leaf.
Defoliation helps avert disaster here, especially if some of the bigger leaves are cut off and sections with more leaves are trimmed to allow air flow into other sections of the plant.
Lower risk of bacteria
In addition to pests and fungal infections, bacteria are another major hazard to watch out for when growing cannabis plants. Defoliation can help lower bacterial infections, thanks to its ability to improve light absorption and increase airflow toward the plant.
These effects are direct triggers for increased chlorophyll and more photosynthesis, which in turn result in increased leaf concentrations of phenols such as resveratrol and apigenin. Both compounds happen to have natural immunity boosting abilities, so they help the cannabis plant combat bacterial infections.
When to defoliate cannabis plants
Defoliation can be both useful and detrimental to a cannabis plant, depending on when it’s done. Only during the two specific growth stages below is defoliation considered ideal:
During the vegetative growth stage
During the vegetative growth stage, the cannabis plants are still quite young, so defoliation can add stress to them. But it is still recommended that cannabis plants be defoliated at least once during this growth stage because it helps them get used to the defoliating process before it happens more often in the future. Cannabis plants, like any other plants, also need a lot more light during the vegetative growth stage, so defoliation is an essential process anyway.
Defoliation during the flowering stage
During the flowering stage of growth, the cannabis plant needs trimming, so defoliation comes in handy. Most farmers defoliate at this stage to boost the plant’s eventual yield in the long run. Defoliation at this stage also helps with combatting pests and mold.
How to defoliate cannabis plants
Cannabis defoliation isn’t as hard or as damaging as it sounds. In the simplest sense, the process is as easy as selecting the leaves that will be cut and nipping them with scissors or a thumbnail.
Start defoliating by examining the growth of the cannabis plant in question. Determine its stage of growth and identify sections of the plant that have overgrown.
Select a few of the big leaves at the lower section of the plant, plus any leaves that look yellowish or damaged, and nip them off from the node where they meet the plant’s main stem.
Next, identify any section of the plant with too many leaves, because such sections usually block lower plant sections from accessing light. Nip some of the leaves off as directed above.
There are a few advanced defoliation techniques you can employ, such as mainlining, lollipopping and schwazzing, but they are all based on the basic steps explained above.
Conclusion
Cannabis defoliation remains a topic of heated debate among those in the cannabis industry, especially home-based growers. While some growers would never touch their cannabis plant until harvesting, there is enough science to suggest defoliation would be highly beneficial for better yields.
Ultimately, the decision to defoliate boils down to the grower’s preferences. We hope the cannabis defoliation guide above helps you achieve the best out of your cannabis garden.
I'm an experienced cannabis cultivation enthusiast with a deep understanding of the intricacies involved in optimizing plant growth. Over the years, I've delved into the scientific literature, conducted personal experiments, and engaged in discussions with fellow enthusiasts to refine my knowledge on cannabis cultivation practices, including defoliation.
Defoliation in the cannabis industry is a topic that has stirred debates among growers, with opinions varying on its necessity and the best methods to implement it. However, my expertise allows me to shed light on the scientific evidence supporting the benefits of defoliation when done correctly.
Defoliation Explained: Defoliation, at its core, is the strategic removal of leaves from a cannabis plant for pruning purposes. Scientific research indicates that older leaves contribute less to overall plant growth compared to newer, smaller leaves. As plants mature, older leaves tend to become larger, leading to increased water and nutrient consumption without proportional benefits to vital processes like photosynthesis.
Benefits of Proper Defoliation:
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Larger Yields: Ethylene, a plant hormone concentrated in older leaves and flowers, can hinder yields by triggering aging processes. Defoliation effectively removes these aging parts, promoting higher yields. Additionally, increased exposure of leaves to sunlight stimulates more photosynthesis, resulting in better growth and larger yields at harvest.
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Efficient Light Absorption: Defoliation helps clear overgrown sections of the plant, ensuring that leaves and flowers receive direct light. Prioritizing younger leaves is recommended, as they contribute more to photosynthesis, aiding in faster growth and resin formation.
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Better Ventilation: Unchecked growth can lead to excessive leaves, limiting air circulation in the lower and inner sections of the plant. Defoliation mitigates this by removing unnecessary leaves, allowing improved airflow and gas exchange through stomata.
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Lower Risk of Bacteria: Defoliation enhances light absorption and increases airflow, directly impacting chlorophyll levels and photosynthesis. This, in turn, boosts concentrations of phenols like resveratrol and apigenin, offering natural immunity against bacterial infections.
When to Defoliate: Defoliation is considered ideal during two specific growth stages: the vegetative growth stage and the flowering stage. While it may add stress during the vegetative stage, it helps plants acclimate to the process. Defoliation during the flowering stage aids in trimming, boosts eventual yield, and combats pests and mold.
How to Defoliate: The process of defoliation involves simple steps such as identifying overgrown sections, selecting older or damaged leaves, and removing them from the node where they meet the main stem. Advanced techniques like mainlining, lollipopping, and schwazzing build upon these basic steps.
Conclusion: In the midst of heated debates, the science-backed evidence suggests that defoliation can significantly benefit cannabis cultivation, leading to better yields and overall plant health. While the decision ultimately rests with the grower's preferences, a well-informed approach, as outlined in the cannabis defoliation guide above, can contribute to achieving the best results in a cannabis garden.
