Plant cultivators are always on the hunt for new ways to strengthen their crops and optimize yields. Defoliation is one tool in a grower's toolbox that may serve to accomplish both these goals. In this grower's guide to cannabis defoliation, you'll learn what defoliation is, pros and cons of the strategy, and tips to make defoliation work for your plants.
From the root word “foliage,” defoliation is the process of removing leaves from plants.
The goal of defoliation is to encourage more abundant yields in a shorter period of time while increasing the overall energy efficiency of the plant. Many plants may benefit from defoliation, such as cotton, cowpeas, palms, and cannabis. One primary purpose of cannabis defoliation is to increase indoor cannabis yields, although removing leaves may be beneficial to all cannabis plants regardless of the grow set-up.
How does defoliation work?
Unlike pruning, which is more aggressive and strips away branches and nodes, defoliation only removes leaves. However, you may opt to defoliate and prune your cannabis plants as well depending on the needs of your plants.
The purpose behind defoliation is to shed light on buds that are hiding under a canopy of leaves. Removing leaves from a cannabis plant during the flowering stage will expose the buds to ample light and oxygen, thereby facilitating quicker and plumper growth. While defoliating plants during the flowering stage is the norm, some experienced growers have been known to defoliate their cannabis plants even earlier in the vegetative stage. But because the vegetative stage presents more challenges, novice cultivators should avoid defoliating during that phase until they gain more experience.
For optimal defoliation results, these factors should coincide:
- The plants are leafy to the point that the leaves are overlapping and on top of one another
- The whole crop is hardy, healthy, and fast-growing to begin with
- Large fan leaves are obscuring some buds, which will fare better when exposed to more light and air
- Plants are in an indoor environment with strong lighting (not necessary, but helpful)
If your plants exhibit the opposite traits — they are fragile, not leafy, and buds are not concealed — then defoliating during the flowering phase will probably not deliver the desired outcome.
In terms of when to defoliate during the flowering phase, many growers suggest one round at the beginning of the stage and another during the third week. But you can always return to the visual clues noted above to determine when is the best time to defoliate your cannabis plants. Most cultivators agree, though, that taking away too many leaves before the end of the flowering period can be counterproductive.
As a rule of thumb, the earlier in the flowering stage you start defoliating, the better.
Whenever you choose to defoliate, start by tackling the large, overlapping fan leaves. Cutting away these leaves provides a breath of fresh air for the buds, setting them free from overgrowth and pointing them towards the light. Probe deep in the plant, from the bottom foundation to clear away space for the buds to flourish.
You may also opt to carefully remove any small stems at the bottom of the plant that are unlikely to bear buds. Anything you remove from the bottom of the plant — whether it's weak stems or bushy leaves — lets the plant's energy rise to the top colas and the lushest part of the harvest.
Pros and cons of defoliation
Depending on how it is executed, defoliation can be a cannabis grower's secret weapon or worst enemy. Below are some of the pros and cons of cannabis defoliation to consider before employing this method.
- Defoliation may maximize light penetration in a cannabis plant, leading to a healthier yield
- Along with an increased supply of light, air will also be available in greater abundance to nurture your cannabis plants and their prized buds
- Mold, mildew, and parasites are less likely to attack your cannabis plants when airflow is unobstructed
- Defoliating dead or decaying leaves is always beneficial and frees up even more energy for plants to thrive
- Proper defoliation can lead to higher quality buds, which equals higher quality weed
- Defoliating the wrong way (i.e., too early or too late) can do more harm than good and may even damage cannabis plants, potentially resulting in slower growth and decreased yields
- Outdoor grows tend not to benefit as much from defoliation as indoor plants do
- Only plants in optimal condition will benefit from defoliation; the process cannot resurrect a dead or weak plant
There are many ways to get the most out of a defoliation practice. Here are the top five grower's tips on how to defoliate a cannabis plant:
- To remove leaves, start cutting near the bottom of the cannabis plant. Sometimes called “lollipopping,” this technique ensures that you only snip away the leaves that are ready for removal.
- Choose the sharpest pair of scissors you can find. Curved scissors are especially helpful for precision cutting.
- Keep the scissors clean to prevent the spread of disease or mold to your cannabis plants.
- Be aware of how much leaf cover you are removing and go slowly. A good benchmark for how many leaves you should initially defoliate is about 15% of the total leaf coverage. You can always return later and defoliate some more, but you can't replace the leaves that have been sliced away. In general, up to 20% is a reliable standard measure of how many leaves to defoliate.
- Educate yourself on different strains and types of leaves. For example, bushy indica plants are prime candidates for defoliation. But you might want to exercise more caution with delicate sativas that have fewer leaves to begin with and therefore fewer to spare.
When done correctly, defoliation is a tool that can help many growers cultivate stronger, more bountiful plants through the simple process of strategically timed cutting.