Topping Cannabis Plants: Benefits, Risks, And How You Should Do It

As a cannabis grower, you've probably heard of other growers using training techniques to maximize their yields. Out of these, there are two types — low-stress and high-stress training techniques — that are commonly used. 

As the name implies, low-stress training techniques don't stress the plant too much while high-stress techniques can be a bit hard on the plant. 

Experienced growers frequently use high-stress training techniques to help their plants grow as best as they can, but beginners are often told to stay away from high-stress techniques. While this is true to some extent, it doesn't mean that you can't try any of them at all. 

There are some methods that even a beginner can master, provided you understand the technique and apply it diligently. And, talking of easy high-stress techniques, there's nothing easier than Topping. 

You've probably heard about it, but now it's time to master it too. 

In this article, we will explore everything you need to know about topping from its benefits to step-by-step instructions, and the right time to do it too. 

What is Topping?

Topping is a common high-stress training (HST) method employed in growing cannabis that will promote bushier growth and can lead to improved overall yields. It involves removing the top of a cannabis plant during its vegetative stage — typically the youngest top tip on the main stem. This allows the plant to focus on producing more main colas instead of just having one big dominant one. 

When cannabis plants grow naturally, they very often concentrate their energy on one large central cola rather than developing a full bush structure with many side branches. Topping is a training method that breaks this apical dominance, which then encourages the plant to grow more evenly in a lateral fashion, triggering many buds.

The Importance of Topping in Cannabis Cultivation

Topping is a superb training technique to use if you're looking to improve the yields of your plants while conserving space. 

Benefits of Topping

Known as one of the best forms of plant training, topping has been proven to increase the cannabis plant’s growth and performance immensely. If done well, it provides several advantages that can lead to healthy plants and huge yields. Here are the key advantages:

• Increased Yields

One of the main motivations for growers to top their cannabis plants is to increase yields. The primary bud site is generally the only cola when left in its natural growth pattern. This may result in a huge main cola, but there are fewer main bud websites. Topping causes the plant to form multiple main colas instead of a single one.

Once you top the plant or cut off its tip, the plant will start redirecting its resources or energy from one single growing point to several tips that start growing. In short, it creates multiple colas and branches which invariably increases the yields with more buds. 

Also, this technique allows you to maximize the use of canopy space as it helps the plant spread out horizontally, which is a huge advantage if you're growing in a small grow tent or don't have a lot of vertical space. A bushy plant with many colas will be better suited for your growing area as it optimizes space and yield. 

• Improved Light Distribution

One more benefit of topping is that it improves light distribution significantly. Rather than having one single dominant cola that overshadows the lower parts of the plant and prevents them from getting proper light, topping makes it easy to create a nice, even canopy as it encourages lateral growth. 

In addition, you'll see that even the lower parts of the plant that otherwise produce popcorn buds will now produce lots of buds as they get sufficient light to conduct photosynthesis. This is because the branches grow horizontally instead of growing upwards as usual, allowing all the branches to get lots of light. As a result, all possible bud sites are exposed to as much light as they can get. 

• Enhanced Airflow

Proper airflow is important for a cannabis plant to grow well. When your plants grow tall and bushy but there's a lack of airflow, you can encounter various problems including pests, mold, and mildew. With one big main stem, the plant grows like a Christmas tree but the airflow will always be restricted.

However, topping reduces this problem as it increases the airflow by helping the plant spread out evenly. Ultimately, this helps your plants grow well as you can avoid heat stress and humidity issues due to increased airflow. 

• Improved Space Management 

Indoor grow tents and rooms don't have the luxury of vertical height. Unlike outdoor plants that can get as tall as they want, it can be a big problem if indoor plants grow too tall as they get very close to the lights. They can get burned easily, and even the buds get bleached and lose their potency and aroma when they get extra close to the lights. Thus, you need a technique that can prevent this problem right in the vegetative stage. If you top the plants during the vegetative stage, they will grow wider instead of getting taller, allowing you to optimize space easily while maintaining an even canopy. 

As you can see, topping has multiple benefits that improve the health of your cannabis plants. It's a technique for growers who want to take their plants' growth up a notch and produce more bud sites while also improving light distribution and enhancing airflow.

Potential Risks of Topping

Although topping is a great way to increase the yield and improve the structure of your plants, there are some associated risks in using this technique as well. Knowing these drawbacks can help you make educated decisions and reduce the impact. Here are some things you need to watch out for:

• Stress on Plants

As you know already, topping is a high-stress technique, so the plant will undergo quite a bit of stress. When you cut off the main tip, the plant will take some time to recover but it also uses a lot of energy to grow new leaves which can be stressful when it is not in perfect health or when growing conditions are less than ideal.

Also, the process can shock a plant and cause temporary wilting, drooping, or slowed growth. This is especially the case with plants already under stress due to nutrient deficiencies, pests, or extreme environmental conditions. Sometimes, the plant will recover slowly but in worst cases, it may never do that at all. 

In addition, so much stress can temporarily weaken the immune system of your plant, leaving it more vulnerable to diseases or pests. And, since stressed plants have a limited inability to fight infections or infestations, it can reduce growth and yield potential even further.

• Timing

When you top a cannabis plant, it takes some time to bounce back and focus energy towards new growth tips. If you don't time it well, it can delay the growth cycle.

So, if you don't give it enough time to bounce back before it begins to flower, the plant may never grow to its full size and produce a good yield. After cutting, the plant needs to fully recover before being able to move onto the flowering stage, so growers need to strategically plan the timing and top at the right time. 

Also, keep in mind that all cannabis strains are different and some may take a longer time for recovery. Therefore, you have to know a few important details about the strain and how it reacts to training techniques. If in doubt, look at the grow diaries of several growers to understand how your chosen strain may react to topping.

• Risk of Infections

Topping a cannabis plant exposes an open wound after the cut. If left uncared for, this wound can quickly become infected and cause more problems, which could be catastrophic to plant health and yield.

Open wounds are perfect for pathogens such as bacteria, fungi, and mold. If the environment is humid or if you use tools without sterilizing them, especially after using them on other plants, there's an increased risk of infection. Symptoms in infected plants include rot, stunted growth, or yellow leaves.

Topping has the advantage of increasing yields and controlling the shape of your plants but comes with risks such as plant stress, long recovery time, and risk of infection. So, be careful and make sure that you take the right steps to prevent issues. 

The Science Behind Topping

Topping is a technique that directly changes the growth of a cannabis plant by altering its natural growing pattern. Cannabis plants generally grow vertically, directing their energies to produce one main stem or a single dominant cola. When you top, you essentially cut off this central growth point, leading to the energy of the plant immediately being transferred into growing other side branches.

Once topped, the plant stops focusing all its energy only on one primary shoot; instead, it distributes it across multiple growing tips. As a result, numerous branches develop from all these growing shoots, promoting a bushier plant. Thanks to all this lateral growth, light penetrates deep into the canopy, encouraging more bud sites that produce more yield. 

To understand this in detail, you first need to know about apical dominance. But, what is it and how does it work?

Apical dominance refers to the tendency of the main central stem (primary apical bud) of a plant or tree to dominate over the lateral branches. This dominance is maintained by plant hormones, particularly auxins that are synthesized at the growing tips. By inhibiting lateral (side) branching, auxins help the plant direct energy and resources to focus on upward growth. Inevitably, this results in a tall plant with a single dominant cola.

However, when you top the plant or remove the growing tip, you disrupt the apical dominance, the production of auxins decreases and the side branches start growing more as well, leading to a higher number of main colas instead of just one.

Note that the success of the topping technique depends on the hormonal response of the plant. Topping a marijuana plant causes numerous hormonal changes, including:

• Fewer Auxins: As you know already, auxins naturally inhibit the growth of lateral branches while promoting vertical growth. When you cut off the tip of the plant, the production of auxins reduces while the capacity to transport it increases, which means the other shoots now get a good resource to grow into huge colas. In other words, they develop with more vigor as they are no longer dominated by the plant top.
• Buildup of Cytokinins: These hormones are essential for encouraging division and growth in the lower portions of the plant. After you top the plant, a reduction in auxins also leads to an increase in cytokinins, so there's a stimulation of new shoots and branches. In short, the plant grows horizontally rather than vertically, promoting a very bushy pattern. 
• Increase in Gibberellins: Gibberellins are also plant hormones that influence your cannabis plant’s development and stem elongation. When you top your plant, these hormones are redistributed which ultimately helps the plant spread more and also helps the plant recover from stress quickly. 

As you can understand by now, the plant goes through various hormonal changes when you cut off the tip or top it. In essence, topping is a training technique that depends on the plant's natural mechanisms to halt vertical growth and force it to grow more horizontally. Growers can then create optimal structures for light exposure, air circulation, and bud size.

When Should You Top Your Cannabis Plants?

Image Credit - DrySlime

Best Time: Vegetative Stage

Topping is best when performed in the vegetative phase of a cannabis plant's life cycle. During this period, the plant is concerned only about growing big and strong, so it's the best time for high-stress training like topping. Similar to other techniques, timing is really important for topping as well since you can end up with disappointing results if you do it too early or too late.

Topping is typically done when your plant has grown 4-6 nodes and before it gets too tall. At this point, the plant is strong enough to bounce back from a topping and has a great root system that will allow it to send energy evenly to every side branch.

If you top during the early vegetative growth, the plant has plenty of time to recover and grow new branches before transitioning to flowering stages. If you top the plants too late, however, there might not be enough time for the plant to bounce back and get its other branches strong and maximize your yield.

However, keep in mind to never top during flowering. Obviously, you don't want to cut off the bud, do you? Also, when your plant is in the flowering stage, it will focus primarily on producing buds and less on vegetative growth. Topping at this phase will simply dwarf the progress of your plant and decrease yields since it just doesn't have the energy or time and energy to regenerate for new expansion.

To sum it up, topping your cannabis plant at an early vegetative stage is the perfect "sweet spot" that will guarantee your plant ample time for recovery before it can produce larger buds.

Here are a few factors you should consider before topping the plants:

1. You should train only healthy, strong cannabis plants. This is because weak plants may not have the resources to recover from stress. You should also not top in case of nutrient deficiencies, or any kind of pests or diseases. Ultimately, they may end up stunted, grow really slowly, or get stressed further. Thus, you should make sure to choose healthy plants that are in a good environment to recover from the stress you put them through. 
2. Examine your plants before you cut off their tips. Most growers wait until the plant has 4-6 nodes before topping while others wait for their plants to have 8 or more nodes beforehand if they are planning on mainlining/ScrOGing and want a specific structure.
3. Certain cannabis strains respond differently to topping. For example, Indicas have a more rounded bushier growth. They tend to bunch up together and develop tight bud clusters while Sativas take on the vertical-like structure growing upward. Topping works particularly well on Indicas as they naturally grow so compact, whereas a more leggy Sativa would be better left to grow into its existing form with careful attention always paid to height control. This doesn't mean you can't top Sativas; you can, as topping allows it to develop more colas but you should control the height using other training techniques like LST. 
4. If you’re growing indoors, topping and LST can help control the height of the plant, but if you have the luxury of growing outdoors, then you can let the plant grow naturally and top just a few times during its early vegetative stage to encourage it to develop more colas. You don't need to control the height and use other training techniques in this instance. 
5. Allow sufficient time to help your plant bounce back from topping before it enters the flowering stage. This is because the plant needs some time to heal from all that stress and redirect its energy to develop new shoots. Typically, the plant needs a minimum of 1-2 weeks to establish sturdy lateral branches.  
6. Think about why you're topping in the first place. Are you doing it for more yields or to just shape the plant? Or, do you want to manipulate the height? This will help you decide how many times you need to top the plant and whether or not you want to combine it with other training techniques like LST or ScrOG. Also, don't go overboard with topping. Too many colas don't necessarily mean that the yields will increase. Be reasonable and let the plant grow healthy without stressing it too much. 

Step-by-Step Guide to Topping

Tools You’ll Need

• Sharp, Sterilized Scissors or Pruning Shears. The cut has to be a clean one to keep the plant safe and prevent infection. Sterilize your scissors or pruning shears with rubbing alcohol or hydrogen peroxide before and after use. This is very important to prevent bacteria or fungus from entering the fresh cut and reducing the chance of infection.
• Gloves to prevent the dirt and oil from your hands transferring to the plants. 
• Stakes for support as some plants may need some support whilst they recover after you top them. 

Identify the Spot You Want to Top

The most important factor that differentiates between a failure and a successful topping is to find the right spot to top. First off, wait until the plant has at least 4-6 nodes. If you top a plant too early, you can stunt the plant! Thus, the plant should have about 4 to 6 sets of true leaves before topping. This keeps the plant in good health and provides enough energy for it to bounce back. 

Next, make sure you top above the node. Specifically, make a cut right above either the fourth or fifth node of growth. This stimulates the growth of two new primary branches below the cut. Topping further up the plant will result in taller, less bushy growth, and topping further down on the stem promotes denser growth.

Practice topping from a well-developed, healthy section of the plant. Find actively growing nodes with healthy green leaves.

Now that we got that out of the way, here are step-by-step instructions to top your cannabis plant successfully. 

1. Prepare your tools: Cleanse your scissors or shears by wiping them down with isopropyl alcohol or hydrogen peroxide. This is very important because it can help the plant from getting infections in the future.
2. Find the Main Stem: This is much more visible than a side shoot. Find the top and check if it has enough nodes for you to top it. 
3. Find the Correct Node: Go to the 4th or the 5th node from the base of the plant. This is where you'll cut so that the plant develops two new main branches that will grow bushier. 
4. Go for a Clean Cut: Now, make a nice clean cut with your sterilized scissors or pruning shears above the node that you chose. Be gentle and slow. The cut should be clean so the plant does not undergo any more stress than it's supposed to. 
5. Monitor the Plant: The plant may become slightly stressed post-topping, and the leaves can wilt a bit. However, this is natural. After all, you have just cut off its main tip and it will display some signs of stress. The leaves should become normal in a day or two. Watch the plant closely for signs of shock or distress during this time. Make sure the plant has the right conditions to recover easily, which means it should have a good source of light, water, and nutrients.
6. Support the plant: Some plants may require support, particularly larger strains. Stake any branches that may droop while the plant rallies to recover.
7. Recovery Time: After topping, let the plant recover. New growth will usually develop from the node below the cut within a week or two. At this point in time, do not stress the plant further with transplanting or HST.
8. Lateral Growth: Over the next week or so, you should observe new main branches (colas) sprouting out of the nodes just below where you topped them. These branches will also produce lots of buds. So unlike one single cola that was supposed to produce clusters of buds, you have several new colas. The plant will be much more bushy than its original growing pattern and you'll also notice an increase in yields, thanks to all those colas.

Simply follow these steps and you rest assured that your cannabis plant will develop much uniformly. Topping the plant is a powerful method of reducing height and size from your plant and if you implement it properly, you'll have bigger, better plants. 

Post-Topping Care

Your job doesn't end after topping the plants. In fact, your success depends on how you take care of the plant after the deed is done. 

Needless to say, you should provide everything the plant needs. Think of it as a sick baby that needs all the help you can offer.

As topping stresses the plant, some plants may find it difficult to stay upright, although this is rare. You're going to be topping when the plant is still in its early vegetative stage, so it won't be all that heavy; however, if you think that the plant is struggling, you will have to use some stakes to support it. There are other things you must follow to support your sick baby. Here's what you can do:

• Maintain the Right Environment 

As you can understand, topping wounds the plant where you cut the tip. This has the potential to weaken the plant and make it vulnerable to various environmental stressors. Thus, you have to maintain the right conditions for the plant to grow properly during its vegetative stage so that it can produce lots of yields in its flowering stage. 

Temperature: The temperature is one of the most important factors to help the plant recover. Whether you're growing in a grow room or tent, make sure that the temps are around 70-85°F (21-29°C). If it gets cooler, it will recover a bit slower but if it gets hotter there will be additional stress and the plant can find it hard to grow. In either case, use fans or heaters to keep this balance in your grow room.

Humidity: For the vegetative stage, maintain a humidity level of 50-70%. The humidity should go up a notch after you top the plant as it accelerates cell regeneration and prevents the plant from drying out. Less humid conditions will prevent the plant from healing faster and your plant may show signs of stress by curling or drying up. 

Air Circulation: It is important that your grow tent has adequate air circulation after topping to prevent hot pockets in the grow room. In addition, a lack of airflow can invite mold, pests, and other diseases that can really slow down the plant during its path of recovery. You can use several fans to ensure there's plenty of air circulation; however, keep the fans away from the plant so it doesn't blow air directly on it. 

• Adequate Lighting

The Light Cycle: Only consistent, balanced light will encourage lateral growth as the plant will be happy. If the light is insufficient, the plant may grow unevenly and the shoots may not develop as vigorously as they should. 

Light Intensity: After topping, make sure you're providing light with the right intensity. The light shouldn't be too intense or inadequate. If it's too bright and your hand feels warm when you place it on top of the canopy, just below the lights, you need to adjust the distance. However, the distance depends on the type of light you're using. Typically, you can place LED lights about 12-24 inches away from the canopy while the plants will appreciate it if you place HID lights at least 18-36 inches away from the canopy. 

Light Duration: Cannabis plants usually like 18-20 hours of light in the vegetative stage. It stimulates powerful growth and helps set the foundation for the flowering stage. In short, the plant develops lots of new branches during the vegetative stage and starts filling them up with buds during the flowering stage. Maintain the right light cycle diligently after you top the plant so that it recovers quickly. Remember, light is food for the plants, so make sure it has enough to conduct photosynthesis and recuperate from the stress. 

Light Distribution: Once you top the plant, it will develop a bushier structure and start spreading out. This is when you have to make sure that the light distribution is uniform and that all parts of the plant have access to light. Position the lights in such a way that a large part of the plant gets good light. You can even use some side lighting so that the exterior branches do not get less light than those closer to the middle.

• Support for Branches

The plant will start developing rapidly if you provide everything it requires. However, new growth can be really weak sometimes if the plant is focusing all its energy on growing too fast. This is a good time to add some structural support so that the new shoots don't sag or break. Let the stakes stay until you harvest the buds as the branches get very heavy with multiple colas bearing buds. 

To support the plants, you can use soft plant ties, bamboo stakes, or even garden wire as long as they are soft and don't cut into the branches. If you're using stakes, plant them into the soil and tie them gently around the branches to support them, but make sure you don't restrict their growth. Stakes will help the branches grow strong and stand up straight.

• LST (Low-Stress Training)

Once you're sure that your topping technique is successful and the plant starts developing new shoots, you can incorporate another training technique called LST to further improve light penetration. This technique will also help you control the height of the plant. However, as the name suggests, LST isn't high-stress like topping and just low-key stresses the plant. It can be used to improve the shape of the plant, like topping. 

To implement this technique, gently bend the branches to the sides and secure them to the sides of your container. Again, you can use soft garden ties and tie them to the branches in such a way that they don't get restricted. This technique is pretty useful to prevent the plant from getting crowded with too many branches as you'll be tying them away from the center of the plant. 

• Pruning

Now, you're probably thinking that we are suggesting way too many training techniques along with topping which is already an HST. However, topping can sometimes result in so many shoots that the plant can be overwhelmed. You can end up with many weak shoots that don't have the potential to contribute much in terms of yields. 

If you notice this, you can prune away lower or weaker growth so the plant can put all its energy into making good quality new colas. This is similar to weeding out weak seedlings, except that you’re doing it to a mature plant. You can also trim lower fan leaves or small branches to remove unnecessary strain from the plant, opening it up for additional upward and lateral growth.

• Nutrient Management

Nutrient management is one of the most important factors in cannabis cultivation. After you top the plant, the plant will respond positively by growing many shoots but they need adequate nutrients to support that growth. However, remember that it's important to provide the right balance as an excess or deficit can have detrimental effects on the plant. 

In any case, cannabis plants need nitrogen-heavy fertilizers during the vegetative stage. This is even more important as they will develop all those new shoots so the fertilizer you provide must have the right balance of nitrogen and other nutrients. Typically, an NPK ratio of 3-1-2 will suffice. This number is not set in stone, though, as it depends on the brand of fertilizer you purchase. Regardless, check the labels carefully to ensure that it has ample nitrogen to support new growth. 

That said, while nitrogen is important, don't forget about phosphorus and potassium. Phosphorus is needed for strong roots and energy transfer, whereas potassium reinforces cell walls and increases the plant's resistance. Therefore, it's important to use a fertilizer that has balanced ratios. 

In addition, remember that although nutrients are important, you should never overfeed the plant even if it's growing multiple shoots after topping. Overfertilization can cause nutrient burn, stress the plant, and make the process of recovery longer. Therefore, watch out for signs of nutrient toxicity where the plant develops dark, waxy green leaves. The leaves may also look burnt. 

To prevent under and overfertilization, establish a proper feeding routine and stick to it consistently. 

• pH Control

Maintain the pH levels of your soil or hydroponic solution within the ideal range for cannabis (6.0 to 7.0 in soil, 5.5 to 6.5 in hydro). Most deficiencies occur due to a pH imbalance, so make sure you prevent that. 

Summary: Topping Cannabis Plants: Benefits, Risks, And How You Should Do It

Topping is a superb technique to stress your cannabis plants just enough to encourage them to grow multiple colas. Rather than developing one single cola, the plant will be forced to produce loads of new shoots that will be filled with buds in the flowering stage, provided you do everything right. 

Although it stresses the plants quite a bit as a high-stress technique, you can ensure that the plant recovers well by providing the right conditions. You can also pair topping with other techniques like LST to ensure that your canopy is uniform. This will promote equal light distribution where all parts of the plant get sufficient light. So, if you have been frustrated with too many popcorn buds due to a lack of light penetration, these techniques can improve the health of your plants drastically and produce juicy, dense buds. 

Just remember not to go overboard with topping as too many shoots won't really help. You can top once or twice and be done with it. If you do it right, the plant will produce ample colas and you can pair it with LST to increase the yields further. 

So, go ahead and top your plants. If you fail, keep at it until you succeed and you'll thank your stars for your persistence.