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Defoliation – A High Risk Way To Increase Yield

Indoor growing is all about maximising space and light. Unfortunately, some cannabis strains can grow thick foliage that overshadows lower nodes, impeding their ability to develop big yields. Defoliation, while controversial, is a great way to enhance light penetration and improve airflow for your cannabis plants.

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There are many ways you can intervene with a cannabis plant’s growth to improve yield quality and size. One of these methods, defoliation, involves stripping a plant of its excess foliage to improve light penetration and airflow.

While it’s a controversial method, we’re firm believers in its ability to improve the quality and size of cannabis yields.

Curved Trimming Scissors

What is cannabis defoliation?

While it’s simple enough, there’s definitely some risk involved with defoliation. Specifically, it’s all too easy to over-defoliate a plant, stunt its growth, and remove nodes that could’ve developed some great bud.

Many growers question defoliation. After all, why would a plant waste energy on growing unnecessary foliage? Well, in nature, cannabis plants use their leaves to store nutrients for stressful times like droughts, nutrient shortages, and pest infestations.

When you’re growing indoors, however, a lot of this excess foliage becomes unnecessary. After all, unlike out in the wild, indoor plants grow in carefully controlled environments with, ideally, perfect temperature and humidity levels and a low risk of pests. In this environment, the thick foliage becomes more of a burden.

That’s where defoliation comes in; by removing some of this excess foliage, not only do you free up some of your plant’s energy (by reducing the amount of foliage it needs to keep alive), but you help your plant make better use of its limited light source. Finally, defoliation also improves airflow around your plants, which in turn helps reduce temperature/humidity issues and the risk of pests/mould.

Note: Some growers confuse defoliation with lollipopping. While lollipopping does necessitate removing foliage, it involves stripping the entire bottom part of a plant, including the nodes (and sometimes removing entire branches), leaving the branches mostly bare like a lollipop stick. Defoliation, on the other hand, involves strategically removing leaves from different areas of the plant, and doesn’t inherently involve removing bud sites or branches.

The benefits of defoliating cannabis plants

To better understand the benefits of defoliation, it helps to first understand that cannabis plants have a finite amount of energy at their disposal to fuel growth. This is governed by several factors, mainly the amount of available soil, the nutrient content of that soil, humidity and temperature levels, and the amount of light.

In an indoor grow room, you’re at liberty to give your plants the right nutrients just when they need them, and can control both temperature and humidity to a tee. However, the amount of light, soil, and space your plants have at their disposal indoors is far less than what they’d get in nature. By carefully removing foliage that won’t support the development of buds, you’ll be helping your plant make better use of the finite amount of energy it can produce with its limited resources.

Removing this foliage will also make it easier for air to circulate around your plants and the room. This in itself has a lot of benefits; not only will it help keep temperature and humidity consistent throughout your grow space, but it will reduce the risk of mould and pest infestations (which naturally flourish in warm, humid conditions).

Benefits of Defoliation
Helps your plant making use of the amount of energy she can produce
Increases air circulation
Reduces the risk of mould and pest infestations
Benefits of Defoliation
Helps your plant making use of the amount of energy she can produce
Increases air circulation
Reduces the risk of mould and pest infestations

Picking the right cannabis plants for defoliation

Removing healthy foliage stresses your plants. Hence, you should only defoliate plants that are 100% healthy; strong, upright stems, green leaves, fast growth, and a well-draining, fast-drying medium are all telltale signs that your plants are happy.

Don’t defoliate any plants that look visibly frail or show symptoms of a nutrient deficiency, over or under-watering, nutrient or light burn, wind damage, or pests/disease. Defoliating these plants will only cause more stress than they can feasibly recover from.

We also only recommend defoliating indoor plants. As we mentioned earlier, cannabis plants actually store energy in their leaves for when they’re exposed to stress. Because outdoor plants are exposed to more consistent environmental stress (like droughts, storms, harsh winds, or temperature/humidity fluctuations) as well as pests, we don’t recommend defoliating them.

Plus, unlike indoor grow lights, the sun changes its position throughout the day and is capable of penetrating even extremely bushy plants, meaning outdoor plants get much more (and far better) light exposure. Thus, they don’t benefit from defoliation in the same way as indoor plants.

Candidates for defoliation
Strong, upright stems
Green leaves
Fast growth
A well-draining, fast-drying medium
Candidates for defoliation
Strong, upright stems
Green leaves
Reduces the risk of mould and pest infestations
A well-draining, fast-drying medium

How to defoliate cannabis plants

The key to properly defoliating cannabis plants is, of course, knowing what foliage to remove. At the same time, it’s also key to know when to defoliate. Ideally, we recommend defoliating your plants once during veg and once during flower.

If you’re an inexperienced grower, only defoliate once during veg. If you are more experienced, you may want to try defoliating multiple times (given your grow schedule allows enough time for plants to recover after each defoliation).

Vegetative phase

We recommend defoliating vegging plants just before you switch them to bloom:

  1. Start by removing big, hand-sized fan leaves first. These tend to overshadow almost anything below them, making it hard for light to properly penetrate your plant’s canopy.
  2. Next, remove any leaves that grow towards the inside of your cannabis plant. These also tend to overshadow important bud sites.
  3. Finally, remove any old, yellowing foliage.

If this is your first time, we recommend defoliating only the bottom half of your plant. If there’s any doubt about removing a particular leaf, play it safe and leave it in place. Don’t remove more than 10–15% of a single plant’s foliage.

If you’re more experienced, however, we recommend defoliating from the bottom of your plant up to 3–4 nodes from the top of the canopy. Healthy plants should be able to handle having 20–25% of their foliage removed (given that you’re not removing anything vital to your plant’s development).

For even better results, combine defoliation with lollipopping and pruning to really help your plant make the most of its limited energy. Finally, once you’ve finished defoliating your vegging plants, give them 2–3 days of rest before switching their lights to 12/12.

Flowering phase

For best results, we recommend defoliating your plants a second time, roughly 3 weeks into the flowering phase. Follow the same steps listed above, but be a bit more prudent about the foliage you remove. Again, if you’re a beginner, play it safe and only remove big fan leaves. Also, remember to be extra careful when handling your plants to avoid disturbing any of their young buds.

After this light defoliation, simply feed and water according to your regular schedule, giving your plants time to develop their flowers.

Knowing what foliage (and how much) to remove

Defoliation is an art form, if only in the sense that there are no definitive guidelines on how to do it. With time, however, you’ll automatically know what leaves to remove from your plants and how much cutting they can handle.

If you’ve never defoliated before, we recommend you always play it safe and stick to removing only the foliage that very obviously impedes bud production. In particular, focus on big fan leaves and interior foliage that’s already covering bud sites.

Quick tips to optimise defoliation

  • The key to getting big harvests indoors is to grow low, flat, and wide. Your plants need a solid canopy to power their growth.
  • Start low. Most of a plant’s bottom foliage is pretty safe to remove.
  • Start slow. It can be easy to get lost in the rhythm of defoliating; then, before you know it, you’ve stripped your plant of half its leaves. Stay focused and move slowly to avoid removing too much. First-timers should aim to remove no more than 10–15% of total foliage at a time.
  • Use sharp scissors. Our curved trimming scissors are great for making precise cuts when defoliating and trimming post-harvest. Remember to always keep your scissors clean to minimise the risk of disease and infection.
  • Different strains can handle different amounts of defoliation. Bushy indicas, for example, tend to cope particularly well with defoliation, whereas sativas tend to naturally produce fewer leaves, and thus can’t handle as much.

Defoliation vs pruning — understanding the differences

Pruning is a separate HST technique that many growers confuse with defoliation. The former is much more aggressive and involves removing entire branches and nodes in addition to leaves. While it might seem counterintuitive, pruning is actually very effective. It helps your plant focus its energy exclusively on the nodes that receive the best light. After that’s done, ideally, it’ll produce the biggest, densest, and most potent flowers possible.

Defoliation, on the other hand, only involves removing the leaves. That said, many cultivators use defoliation alongside pruning to optimise production, or they’ll use it alongside lollipopping, which we explained in more detail above.

Give cannabis defoliation a try!

To really maximise your plants’ potential, you’ll want to combine defoliation with other training techniques like LST, main-lining, lollipopping, topping, and super cropping. As you get more experienced, you’ll learn how to finesse these techniques to produce bigger, tastier, and more potent harvests. No matter what you do, we hope you enjoy the process!

Defoliation is a controversial cannabis growing technique that involves stripping plants of excess foliage. Read on to learn how to defoliate your weed plants.

Nebula’s Flowering Stage Defoliation Tutorial

Introduction to Bud-Based Defoliation

What is cannabis defoliation, and why/how does removing leaves from a cannabis plant increase yields?

The point of defoliation is to “hack” your plant’s natural processes in the early part of the flowering stage to cause it to grow its buds and colas differently. You’ll notice in the pictures below that the plants have focused purely on bud development. Growers achieve this by removing fan leaves from healthy marijuana plants during early bud development to keep the plant “focused” on growing buds instead of leaves.

Bud-Based Defoliation is the only way to achieve results like this!

In the wild your plant will spend some amount of energy on buds, as well as some amount of energy making and maintaining leaves. However, if you defoliate your cannabis plants early in the flowering stage, you will change the plant’s natural growing patterns.

Without as many leaves at the moment buds are first forming, your plants puts more energy into making colas, and the colas will be longer, thicker, and go down further into the plant.

Theories Why Bud-Based Marijuana Defoliation Works…

  • Cannabis is wind-pollinated, so it doesn’t fatten any buds except the ones that have access to wind. Defoliation exposes the more of the buds to a breeze.
  • Cannabis buds seem to get fatter when they’re exposed to strong, direct light and defoliation exposes the buds to light.
  • It’s possible the plant focuses on bud sites during the initial part of flowering because it simply doesn’t have leaves to put energy into

Did You Know? There are other commercial crops, like cotton, which also need to be defoliated early in the flowering stage to produce the best quality and yields!

Whatever the reason, defoliation works to dramatically increase your cannabis yields when you do it correctly!

Only buds that get exposed to direct light ever get a good size. If your plant is very bushy like this one, you are losing out on potential yields because the hidden buds stay small. The buds would have been longer and bigger further down into the plant if it had been defoliated in the early floweirng stage.

Here’s another example of cannabis plants that would have benefited from defoliation. Notice how short all the buds are. They end where the bushiness begins. If the grower had exposed the colas, they would have fattened much deeper into the plant!

Many growers write in to tell us how defoliation was the secret sauce they needed to take their growing skills to the next level. In our growing forum we have some growers that are conducting defoliation and have taken the technique to new heights!

Ready to learn how to incorporate defoliation into your own cannabis garden?

pic by Ricky (a first time defoliator!)

It’s pretty well-accepted in the cannabis growing world that defoliation can increase yields in some situations, but what’s the “best” way to defoliate? That’s a common question without an easy answer.

The truth is that everyone has their own ideas about the best way to defoliate! If you ask 10 different growers, you’ll get 10 different answers! And you’ll probably find at least one person who claims it doesn’t work at all.

Today, I’ll share my own personal defoliation timeline and tactics (which I’ve developed over the last few years)!

Note: Some equatorial Sativa and Haze strains naturally grow tall and “leggy” with thin leaves and lots of exposed stem. These strains may never produce enough leaves to get bushy even in the best environment, and may look like they’ve naturally defoliated themselves. When this happens there’s no need to defoliate plants further. However, many (if not most) strains produce some amount of leafiness that needs to be removed for optimal growth indoors.

You may not need to defoliate if you see lots of stem and bud sites are already exposed. Some strains naturally grow leggy enough that they don’t need much, if any, defoliation to expose bud sites or increase air circulation!

Vegetative Stage Defoliation

I don’t remove leaves in the vegetative stage to the same extent I do in the flowering stage.

Most defoliation in the vegetative stage is used to thin out the plant if it starts getting really bushy. Making sure there’s always airflow through the middle and under the bottom of the plant will help plants grow better. Good airflow also prevents White Powdery Mold (WPM), a common problem when you have leaves laying on top of each other.

In my opinion, if you can’t see through the plant, and/or there’s no light getting through to the bottom, it’s too bushy for proper airflow!

These vegetative stage plants are too leafy! Notice how the floor is in shadow? They’re ready for a haircut!

When it comes to plant training, the focus in the vegetative stage is on getting the shape of the plant correct (flat and wide like a table), and making sure there’s multiple main stems/colas under the grow light.

When I’m growing my own cannabis plants, I don’t start defoliating aggressively until I’m in the flowering stage.

Flowering Stage Defoliation

Right before the switch to the flowering stage, I remove any leaves and tiny growth tips on the bottom parts of the plant that aren’t getting light anymore (sometimes called “lollipopping” the plant).

It is important to do right this before the switch to flowering so the plant is putting all its effort into the top bud sites instead of the lower bud sites that will never grow into big buds no matter what you do.

Some growers call the technique “lollipopping” because you’re making the bottom bare like a lollipop stick 🙂 Though some growers also remove bud sites while lollipopping, for you first grow, I recommend removing all the leaves below the line, but leaving the bud sites (growth tips at the base of each leaf) alone. This helps ensure you have as many places to make bud as possible. I’ve found that leaving extra bud sites doesn’t seem to reduce your yields as long as you’ve defoliated the plant properly, but removing too many bud sites definitely hurts your yields!

This grower stripped all the buds sites from the bottom of the plant while lollipopping, resulting in shortened colas. I’ve done this, too! His yield would have been bigger if he’d allowed those bud sites to continue further down on each stem!

To prevent the problem with the plant above, avoid removing or damaging future bud sites whenever defoliating. It’s easy to accidentally damage bud sites when they’re just tiny pre-flowers like this one, so be extra careful when removing leaves!

After you’ve stripped all the leaves from the bottom your plant, it’s time to remove most of the remaining biggest fan leaves (though you’re not going to completely strip the top part as much as before). You’ll be leaving any small fan leaves as well as the top few pairs of big fan leaves of each cola completely untouched. After this step, the plant will be almost all “bones” and bud sites, with few big fan leaves except at the top.

Flowering Defoliation #1 (Immediately Before Switch to 12/12)

Before Defoliation

After Defoliation

I leave a few extra full size fan leaves at the top of each cola because I believe it helps power the growth of the colas during the flowering stretch so they get as long as possible. Make sure to remove only leaves during defoliation, but not bud sites! I have found after trying it both ways that removing bud sites while lollipopping/defoliating often hurts your yields!

Flowering Defoliation #2 (Last Major Defoliation) – Week 3 of Flowering Stage

This is what that plant looked like 3 weeks later. I didn’t remove any leaves in that time. The plant has gotten far taller due to the flowering stretch, and is completely covered in leaves again!

Usually by around week 3, a bunch of budlets have formed. At this point I remove all of the major fan leaves one last time. You’re forcing the plant to focus on the buds during this crucial phase of their development!

After that, I’m done with the majority of defoliation! From week 3 and on, I only remove leaves if they’re covering a bud site (and I can’t tuck the leaf away) or if the plant starts getting too bushy through the middle and bottom. Each leaf provides energy to the plant, and I cherish them… unless they get in the way! 🙂

Harvest – 7 Weeks Later I Harvested This!

If you want to copy these results for yourself, refer to the following quick summary!

Nebula’s Bud-Based Defoliation Technique (Quick Summary)

So basically, my (personal) cannabis defoliation technique could be summed up like this:

Vegetative Stage

  • Plant Training– Train plant(s) to grow into a generally flat and wide shape, so they fill your grow space like a table. This makes it so you have multiple colas located at the top of the plant and close to the light. Or choose a Sea of Green setup (growing many small plants) and skip the training!
  • Defoliate the middle and bottom of your plant(s) whenever you can’t see light coming through them. When the middle is completely dark it means the plant is too bushy!

Right Before Switch to 12/12

  • Do this step when plant is about half the final desired height (since it will about double in size after the switch to 12/12)
  • Lollipop the plant (completely strip the lowest leaves on the plant that will never get light, leaving the bud sites intact)
  • Remove big fan leaves on the upper part of the plant (making sure not to damage bud sites) until plant is not leafy. If you can easily see your plant’s stems it’s a good time to stop.

Week 3 After Switch to 12/12

  • One Last Defoliation at Flowering Week 3 – Now that you’re three weeks into the flowering stage, do another major removal of just about all the fan leaves. Make sure to especially take any big leaves with long stems, or leaves that are covering bud sites! Again, avoid removing or damaging any developing buds!

After Week 3, I only defoliate huge fan leaves that can’t be tucked away. Otherwise I just wait until harvest and reap the rewards!

Defoliation is a technique, but it is also an art! The above instructions should get you started but cannabis plants are like big bonsai trees and you’ll eventually learn how to defoliate without hesitation. It’s fun to try to alter the growth patterns of cannabis plants and I encourage you to experiment with your own plants and develop your own particular defoliation style and rhythm!

Have you tried defoliation yourself? Send us pictures!

You Might Be Interested in One of the Following Cannabis Plant Training Tutorials…

Detailed Breakdown of Training Techniques​

Nebula’s Flowering Stage Defoliation Tutorial Introduction to Bud-Based Defoliation What is cannabis defoliation, and why/how does removing leaves from a cannabis plant increase yields? The