Defoliating your plants is the process of removing leaves to allow more light and airflow to reach your buds. Not only does defoliation promote growth and boost your yields, but it also helps prevent diseases like powdery mildew (PM). It can even help prevent the development of pests like mites. While it might seem counter-intuitive, getting rid of plant matter at specific points in your plant’s life cycle will actually lead to more weight when you harvest.
Defoliating is also called “de-fanning” because it involves removing your fan leaves. When you remove fan leaves from your plants, you want to make sure you have ample light penetration through your canopy. Don’t be afraid to go “too hard” when defoliating your plants. They actually like it. You’ll see that within a few days of defoliation that your plants are taller, your buds are developing faster, and your plant is healthy.
In veg and early flower, you want to defoliate and lollipop at the same time. We’ll go over lollipopping in another post.
Why Should I Defoliate my Cannabis Plants?
There are a couple reasons to defoliate your cannabis plants. Defoliating your plants will help you minimize LARF, or underdeveloped buds that don’t get enough light or air. In addition, defoliating sends hormonal signals to your plant to make it grow bigger and heavier.
Plants have three main hormones that control growth: auxins, gibberellins, and cytokines. These hormones are growth regulators that affect the size and density of your buds. When you defoliate your plants, you’re trying to manipulate these hormones to get the biggest and heaviest yields.
One of the ways you can manipulate these hormones is through pruning, including defoliation. Defoliating your plants makes them release these hormones. That in turn accelerates your plant’s growth. This is especially noticeable during the early weeks of the flowering cycle, when you’ll see your remaining fan leaves pointing up towards your light source. This is called “praying.” When your plant is praying, it’s happy and growing as quickly as possible. (if they are too far up it can be a sign of light stress)
Last but definitely not least, defoliating is a way to release low levels of stress in your plants. If you stress your plants out a little bit, they’ll grow bigger. It’s kind of a “what doesn’t kill you makes you stronger” scenario. Defoliating is pretty low-stress, so the chances of causing your plant to change into a hermaphrodite are pretty low.
When Should I Defoliate my Cannabis Plants?
It’s important to make sure defoliate your plants at the right time. For example, if you wait for too long into your flower cycle to defoliate, you may find your plants have already developed LARF or infections. That’s why it’s important to know the best times to prune your plants and stick to your schedule.
You want to make sure you defoliate your plants right before you flip them from veg to flower. This way they’re ready to start growing immediately once they enter the flower cycle. The first couple weeks of growth in the flower cycle produce a lot of fan leaves. Once you hit your third week of the flower cycle, you want to defoliate hard again.
Make sure that you remove enough plant matter for light and airflow to reach every area of your plant. Finally, you can defoliate one last time around week seven of flower if you need to. This will ensure that your nugs have plenty of light and airflow as they finish up. You’ll notice that the buds that aren’t in direct light are different colors than parts of the plant that were in direct light. Over the last few weeks of your flower cycle, direct light will cause these areas to change color and grow denser.
When you’re seven weeks deep into a flower cycle, you want to make sure nothing goes wrong before harvest. You don’t want to ruin all that hard work!
How Much Plant Matter Should I Remove when Defoliating?
There are a couple schools of thought here. One technique, called “schwazzing,” involves removing every fan leaf from your plant. This technique is commonly used in gardens with lots of plants that are all close together. It’s one of the only ways you can create adequate air flow if you have more than four plants per four-square-foot area.
However, schwazzing can be time consuming. As a result, if you don’t have more than four plants per four-square-foot area, you probably don’t need to schwazz. Instead, of schwazzing, I usually leave the top three fan leaves on each stem. Fan leaves are like your plant’s solar panels. Therefore, you want to leave a few to help promote plant growth. There is one exception to the three-leaf-per-stem rule though. When you’re completing your late-flower (week seven) defoliation, you can go ahead and get rid of every fan leaf.
If at any point you look at your plant and think “oh no, I took off too many fan leaves,” don’t worry. You didn’t. Take a deep breath. They’ll be okay.
The Proper Way to Remove Leaves
You might think that it’s silly to ask how to remove a leaf from a plant. You just take it off, right? Wrong, bucko. Some people like to use pruning shears to cut the stems of the fan leaves. However, this is not what you want to do. If you cut open the stems of the leaves and leave them on your plant, it creates a vector (or access point) for infections. That open stem is a great way for something like PM to get into your plant.
Instead, pull downwards on the leaf until you feel the base of the leaf’s stem come off of the plant with a satisfying pop. Removing plants this way doesn’t leave an opening for diseases to infect your crop.
Knowing how to defoliate your plants is a great advantage for a grower. Proper defoliation will keep your plants healthy and encourage your nugs to grow as big and dense as possible. On top of that, the plants love it. You’ll see their reaction in the few days after you defoliate. And there’s nothing better than happy plants!