Root-Bound Cannabis: Causes, Effects, And How To Prevent It

No one likes being confined physically. It's no wonder many companies now prefer open floor arrangements and are doing away with cubicles. After all, cubicles are synonymous with a boring workplace and hamper creativity more than they improve focus. 

Something similar happens to your plant when they are metaphorically constrained by the “cubicles” — in other words, the container. When this happens, your plant loses its ability to grow further and develop a bigger yield. Such a plant is considered root-bound, which is a common problem for new growers. Ultimately, you may not be happy with the results. 

But what is a root-bound cannabis plant and how do you prevent it?

In this guide, you’ll learn everything you need to know about root-bound cannabis and how to avoid it. 

What is Root Bound Cannabis?

As a cannabis grower, especially if you’re a beginner, one of the problems you need to prepare for is your cannabis plant getting root-bound. This problem arises when your cannabis roots grow bigger than the container can handle, due to which the roots no longer have any further space to grow and develop. 

This can cause several problems for your cannabis plant. For a healthy cannabis plant, root development is essential because the plant’s growth depends on the size of the root ball. The bigger the roots get, the more nutrients they can absorb, resulting in a bigger plant. 

When the roots can no longer expand due to the container constraints, they can no longer sustain the plant’s spurting development since they can’t absorb more nutrients and water that are required for the plant to grow. In minor cases, this leads to stunted growth, but if the problem is not addressed promptly, it can even cause nutrient deficiencies and malnutrition in the plant. Eventually, the plant can even succumb to it. 

Root-bound cannabis is more likely to occur in an indoor setup where you use pots or containers. However, some outdoor cannabis plants growing in containers can also experience this problem once in a while. In rare cases, root-bound cannabis can also occur in plants growing in the soil, where the growth is constrained by rocks or other objects in the soil. 

Typically, root-bound cannabis shows itself in various ways, such as the following:

• Stunted or slow plant growth 
• Discoloration or yellowing of leaves 
• Drooping leaves or branches 
• Nutrient deficiencies 
• Roots growing out of the drain holes on the container 
• A dense root ball 

It’s important to know that root-bound cannabis may not be a problem for some growers. While you may want a bigger cannabis plant, some growers prefer to keep their plants small and discreet. In such a case, growers get their cannabis root bound so it can no longer grow larger than required. Here, root-bound cannabis is a growth-limiting technique. 

Difference Between a Root-Bound and Pot-Bound Plant

Root-bound and pot-bound plants are quite different from one another, and while the difference doesn’t matter much for cannabis growers, it’s worth knowing about it nonetheless. 

Essentially, a plant becomes pot-bound when the container is too small for the roots, which leads the plant to get root-bound. Some species of plants naturally grow dense roots regardless of the container size, so they are naturally root-bound.

When we consider cannabis, the plants getting root bound is not a result of natural phenotype but because of the container, and hence, it must be treated as such. It’s an arbitrary difference. But if you are growing any other plant, it’s always good to know whether your plant is naturally root-bound or otherwise. 

How is Root Bound Cannabis Bad?

We already glanced over some of the symptoms of root-bound cannabis, but why exactly is this such a bad thing for your cannabis plants? Let’s dive into the symptoms and effects of root-bound cannabis. 

1. Soil Drying Out Too Fast

One of the first major symptoms of root-bound cannabis is that the soil will dry out faster than usual. This will have you watering your plant every day or more frequently. Typically, it occurs because the roots are absorbing more water than what the container holds. Remember, cannabis plants are thirsty and need a lot of water. 

2. Nutrient Deficiencies or Malnutrition

Root-bound cannabis occurs when the roots grow big, which is when they start consuming more and more nutrients from the soil. However, there’s a threshold to this — the plant grows big, and the roots no longer get enough nutrients to sustain the bigger plant since they can no longer expand. 

When this happens, your cannabis plant starts showing signs of nutrient deficiencies like yellowing leaves, spots, wilting, crumbling, etc. Of course, it could be a pH imbalance or an actual nutrient deficiency, so you must check for these usual suspects before you peek at the roots. However, if all the tricks you try to cure this nutrient deficiency still persist, you need to check the roots as they may have been root-bound. 

3. Slow Growth And Reduced Yields

Stunted growth of the plant is another symptom that your cannabis plant may be suffering from being root-bound. This can show itself in many ways, including the leaves and buds not growing big enough, the plant not reaching the expected height, or the foliage being less dense than usual. 

If you think your cannabis plant is not growing well, the plant's roots could be bound and this problem is especially bad during the flowering stage when transplanting the plant isn’t ideal. 

4. Nutrient Burns 

On the other hand, your cannabis plant may also showcase signs of nutrient burns, which occur when your plant gets more than the required amounts of nutrients. This happens due to overfertilization and common symptoms of this include tip-bent leaves, brown or yellow leaves, or drooping branches.

This is a rare symptom but it can still occur due to the roots being so dense that only certain nutrients get to it whereas the rest do not or because the massive root ball is absorbing more nutrients than required to sustain the plant. This can cause nutrient burns sometimes. 

5. Sick Plant

Sometimes, you may not be able to pinpoint anything but your plant will look sick without any clear cause. It’s hard to describe this symptom because it's so different for each plant and strain, but you’ll know your plant is sick when you look at it. This could be happening due to nutrient deficiency, water deficiency, or nutrient toxicity. 

6. Too Much Growth 

Similarly, your cannabis plant may also grow too big for the container to support it physically. This can occur when the roots grow dense and get enough nutrients to support the plant’s growth, leading to the plant growing tall and potentially tipping over. 

How to Prevent Root-Bound Cannabis?

As the saying goes, prevention is better than cure, and that is exactly what you must do while growing cannabis. The more problems you avoid, the healthier your plant grows with minimal risks. And it’s best not to wait for the problems to fix them — you wouldn’t remove the pizza from the oven after it’s burnt, right?

So, you need to prevent root-bound cannabis in the first place and, fortunately, it’s pretty easy to do. It requires you to be a more proactive and smart grower, and here’s how you can do that. 

1. Use a Right Sized Container or Pot 

The first step you need to do when growing cannabis is to use the right-sized container for your plant. Of course, your little seedling can grow just fine in a tiny pot, but it will soon outgrow that container and you’ll have to move the plant to a bigger container. The question is: is the new container big enough for your cannabis plant?

When choosing a pot for your cannabis plant, you need to keep a few things in mind, such as the following:

• The size of your grow room — the bigger the container, the bigger the plant, so you need to pick the size according to the space you have
• Your budget. If you’re tight on budget, it’s better to use a bigger container from the get-go but don’t forget to compensate for the bigger pot by watering the soil more 
• The expected size and yield of your cannabis plant; if the strain you’re growing is known to grow massive and produce big yields, you need to pick a bigger container 

Regardless of the size of the container or the plant, most growers will have to transplant their cannabis plants from one pot to another at least once during their plant’s growth cycle. This is because it’s more efficient to grow plants in the right-sized container to minimize water and nutrient loss to drainage. 

Ideal Pot Size for Cannabis 

So, what’s the ideal size for cannabis plants? Pots come in many sizes and shapes, and it all depends on the type of strain you are growing and your preferences. However, a good starting point for indoor cannabis is to use 2.5-gallon containers. Avoid using anything under 2 gallons as that’s too small and the risk of root bound is high. 

Here’s a generic guideline on the pot size you may choose depending on your plant’s size. Remember, this is just a starting point and the same for your plant may vary drastically. So, research well. Here’s the guideline:

• 2 gallons for a plant that’s about a foot in height 
• 3 gallons for a plant that’s two feet in height 
• 6 gallons for a plant that’s a meter in height 
• 10 liters for a plant that’s four feet in height
• Over 12 gallons for a plant taller than five feet 

So, in the early growth stage of your cannabis plant, you can use smaller pots since they are easier to manage and allow for excellent seed germination until the seedling develops a couple of pairs of true leaves. 

Post that, you can transplant it in a bigger three to six-gallon container, depending on the strain and so on. Again, it’s difficult to make a blanket statement about the right container size, so don't hesitate to research well and ask other growers about the best container size.

Pros and Cons of Each Type of Container

Here are the pros and cons of each type of container so you can make the right decision. 

1. Plastic Containers

Advantages

• Cost:  Plastic pots are budget-friendly and available almost anywhere. 
• Light: You can move them easily, making them suitable for outdoor, indoor, and greenhouse cultivation.
• Size: They are available in many sizes, so you can use different sizes for your plant’s various stages of growth. 

Disadvantages

• Limited Breathability: Very little airflow, so the plants can’t breathe much, which will reduce root aeration and water drainage.
• Heat Retention: Absorb and retain lots of heat that may cause temperature issues in the root in hot climates. 

2. Fabric Pots

Advantages

• Excellent Aeration: Lots of airflow and oxygenation for roots that allow the plants to breathe and also reduce the risk of roots getting bound. 
• Prevents Overwatering: Dry pretty quickly and prevents overwatering.
• Easy Transplantation: You can transplant the plant easily with fabric pots. 

Disadvantages

• Durability issues: Not as durable as plastic or ceramic pots. 
• Frequent watering: You may need to water them more than you would with plastic or other alternatives as the pots dry up quickly. 

3. Ceramic or Terracotta Pots

Advantages

• Aesthetic appeal: Ceramic pots have an aesthetic appeal and can complement various settings.
• Stability: Typically heavier and can support heavy cannabis plants. 
• Good drainage: Ceramic pots often come with drainage holes, which help prevent overwatering.

Disadvantages

• Limited airflow: Ceramic pots don’t let the roots breathe as much as fabric pots, thereby affecting the root health eventually. 
• Fragile: Mishandling can result in breakage or cracks, making them less durable.

4. Air Pots/Air Pruning Containers

Advantages

• Encourages air pruning: Promote air pruning of roots and prevent them from getting bound inside the container. 
• Enhanced growth: Air pruning helps with extensive root systems. 

Disadvantages

• Cost: Very expensive compared to other types of containers

As mentioned already, remember to consider various factors including your budget, personal preferences, and your growing space before choosing containers. As you can understand, choosing a good container is just one aspect of preventing root-bound cannabis, and there are various other things you should do to prevent the roots from getting bound inside the container. 

Get Yourself Some Fabric Pots

Most growers prefer fabric pots as they are affordable and improve airflow in the rhizosphere. This airflow is obviously crucial for the roots for breathing, but it also offers another benefit. 

The air in the root zone signals the roots when it’s time to stop. In a regular container, the roots don’t sense air in the atmosphere which may signal them to stop growing, and they keep growing until they become too dense and crowded. However, with a fabric pot, once the roots reach the edge of the container and sense air, they stop growing, which prevents them from getting overcrowded. 

Additionally, fabric pots also improve drainage of the plant, which is always a benefit. This prevents the roots from drowning, which can happen when the soil is not aerated enough — the water pools and is slow to evaporate. 

Since fabric pots allow water to drain out from the sides and the bottom, it ensures that there’s no water logging. Thankfully, the roots get plenty of oxygen but you also prevent the risk of root rot or slimy roots. 

Fabric pots have the potential to prevent most root-related problems, but you can’t deny their high cost, either. They can be expensive compared to regular containers or pots. But we argue that the higher cost is worth it. 

You can find fabric pots in your local horticultural or hydroponics store, and while they come in a variety of materials and construction, the benefits largely remain the same. So, it won’t hurt to try out cheaper fabric pots before you splurge your ice cream money on fabric pots. 

2. Training and Pruning

Some growers prefer not to train their plants, which is okay. However, you don’t train the plants just to make the plants look good or increase the number of colas. Training plays a key role as it not only shapes the canopy but also influences the health of the roots significantly. 

• Encourages the roots to spread: Techniques like low-stress training (LST) involve bending and securing branches to the sides of your container. This helps the plant to spread its roots rather than solely focusing on growth downwards which can cause root binding. 
• Promotes air circulation: When you manipulate and open up the canopy during the training process, there’s an increase in airflow around the plant. This enhanced aeration, especially around the root zone reduces the chances of moisture buildup and potential root rot.
• Light Exposure: Most training techniques are designed to ensure that every part of the plant receives sufficient light. As more parts of the plant actively engage in photosynthesis, the plant will be able to absorb nutrients and display healthy growth. 

Next, you can also prune the plant frequently to prevent root binding. Most people assume that pruning is unnecessary but it’s not just about trimming parts of the plant; it can also positively impact root development;

• Root Pruning; During transplanting root pruning is used to trim or eliminate tangled or circling roots. This technique encourages the growth of a more extensive root system. By preventing root spirals you minimize the risk of roots getting bound in containers.
• Canopy Pruning: Trimming the foliage, stems and branches obstructing light within the canopy ensures that all parts opf the plant get some light. Also, it can help the plant distribute its resources efficiently, thereby making the plant healthy and reducing root stress. 
• Removal of Dead or Diseased Tissue: BY removing dead leaves or any parts of the plant infected with some disease, you will maintain a clean environment around the plant and reduce the likelihood of pathogens infecting both the roots and other parts of the plant.

3. Be Meticulous About Transplanting 

As mentioned earlier, you will have to transplant your cannabis plant during various phases of its growth stage. But don’t just do it whenever you fancy; instead, have a plan and stick to it unless the conditions force a change. This will keep you prepared with everything ready to go before the roots become bound. 

Ideally, you can transplant seedlings after two weeks of growth or when they have already developed three sets of true leaves. By keeping these two tips in mind, you’ll be able to execute the first transplant perfectly. 

As for the vegetative stage, you may need to transplant your cannabis once or twice (and sometimes more) depending on its growth speed. Generally, expert growers prefer to transplant multiple times and grow plants in smaller containers so they get access to all the nutrients, but if you’re not confident about the timing, using a bigger container and having fewer transplants will not hurt. 

Typically, the final transplant into the final container occurs right at the end of the flowering stage. So, avoid transplanting the plant during bloom unless you absolutely have to. Transplanting during the flowering stage can put stress on your plant, but always try to take a more conservative approach so it does not come to this. 

In addition, make sure you’re extremely gentle while removing the plant from its container and placing it into the new one so you don’t damage the stems or roots. Also, the environment should be stable, which means that the humidity, temperature, and even light should be consistent. Water the plants adequately to minimize stress. If possible, you can use products that reduce transplant shock and promote rapid root growth. 

How To Fix Root Bound Cannabis?

Well, you’ve done everything and followed the right steps mentioned above to prevent root-bound cannabis, but still ended up with root-bound cannabis. That’s alright — happens to the best of us. One of the most fun aspects of growing cannabis is unpredictability, and sometimes, you pull the wrong card out of the stack. 

However, it’s important to note that root-bound cannabis is a serious problem that can reduce your plant’s growth and yield at best and kill it at worst. Fortunately, fixing root-bound cannabis is a straightforward process and easy to fix if you follow the right steps and act promptly. 

Here are some ways of fixing root-bound cannabis. 

1. Water the Plant Properly 

The first step to do if your cannabis plant is root-bound is to water it well. Doing so will help moisten the roots and rhizosphere, which will make the steps that follow much easier to execute. Ideally, it is recommended that you water for a couple of hours before you move on to the next step. 

2. Get Your New Container Ready 

The way to fix root-bound cannabis is to transfer the plant to a bigger container, so, you need to prep your big container. Use the guidelines mentioned earlier to figure out the right container size for your cannabis plant. 

Once you have the right-sized container, fill it ⅔ away with fresh soil, and use your fingers to punch a hole in the center of the soil. The hole should be big enough for the root ball of your plant. 

You can also water this new soil to dampen it, allowing the soil to hold nutrients as it welcomes the roots while also making it easier for the roots to settle into the soil. 

3. Remove the Plant From the Container 

Now the transplant begins. You need to remove the plant from the original container where it got root-bound. Here’s how you can do that:

• Place your palm on the soil with the plant’s stem between your middle and ring finger (or whichever is comfortable) 
• Tip the entire plant upside down along with the pot 
• If the soil is moist and everything is well, the plant will slide out of the pot with the soil — if not, you can always tug your plant a bit or try loosening the soil with your fingers 

Remember to be gentle, though. 

4. Loosen the Roots 

Once you have your plant out of the container, you need to loosen the roots, which can be done by massaging the roots. Remember to be gentle and try to agitate the roots so they come apart without breaking. Do this until the root ball is no longer dense. 

In some cases, you may even have to prune the roots if they have grown too dense. Don’t worry, root pruning is one of the lesser-known training techniques that work wonders for cannabis plants. So, use a sharp scissor or blade to prune away any parts that are stuck, but remember to be gentle and conservative. 

You don't want to cut away excessive root matter, especially the tap roots, which are crucial for your plant’s health; cutting them off is inviting trouble to your plant — totally not recommended. 

5. Wash the Roots

The next step is to clean the roots, especially if they feel slimy or have developed root rot. You can still plant the plant without washing the roots if they appear healthy, but being cautious never hurts anybody. 

If the roots look white, they are good and may not require cleaning, but they absolutely require a good rinse if they appear wet and brown or have started turning to mush. So, start by pruning the infected areas and wash the roots with hydrogen peroxide diluted in water. Don’t forget to rinse the roots at the end. 

6. Plant It In the New Container

With all said and done, you can finally plant your cannabis in the new container. Start by placing the roots into the hole you punched into the soil and be extra gentle during this time. Try to spread out the roots as much as possible. 

Then, cover the roots and any gaps left between them with more soil. Avoid compacting the soil too much here as it will affect aeration. Water the plant and your plant will recover in a few days. 

Summary: Root-Bound Cannabis: Causes, Effects, And How To Prevent It

Root-bound cannabis occurs when the plant grows too big for the container, where the roots no longer have more space to expand and end up turning into a dense root ball. This is a serious problem that can cause many issues for your plant, including stunted growth, nutrient deficiencies, subpar yield, and even death. 

Fortunately, root-bound cannabis is easy to prevent with a few basic steps: choose the right sized container, consider getting fabric pots, and transplant your cannabis on time. If you still end up with root-bound cannabis, transplant your cannabis to a bigger container, and don’t forget to rinse the roots and make them less dense during the process.