Root bound cannabis: Signs, effects, and how to fix it fast

Root bound cannabis plants can seriously stunt growth and limit your yields - but it’s a problem with a solution. 

If you’re noticing slowed growth or yellowing leaves, your plant could be struggling with root binding. 

Left unchecked, root bound cannabis won’t absorb water and nutrients effectively, which quickly drains its vitality and productivity. 

In this post, you’ll learn how to recognise root binding, its effects, and the best ways to fix it. 

We’ll help you keep your plants healthy and thriving with clear, proven steps.

Disclaimer: Any information given on this site is for educational purposes only. Please ensure if you’re growing cannabis, you’re doing so by the law and subject to appropriate permissions and licenses of the applicable country.

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What does root bound mean?

Being root bound refers to a plant’s roots growing too large for its current container and wrapping around each other in search of more space.  

This happens most often when a large cannabis plant grows in a small container.

It can also happen when a plant stays in the same container for too long without being repotted into a more appropriate size container. 

For cannabis plants, the problem can start when roots run out of room, and it becomes more pronounced as they form a tight, tangled root ball. 

You may notice roots poking through drainage holes or visibly circling around the bottom of the pot. 

When this happens, the plant struggles to access enough nutrients and water from its growing medium, which can severely impact its growth above ground.

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Causes of root bound cannabis plants

Root binding typically happens when a plant outgrows its old container. Here are some common causes:

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Small pots for big plants

If you’re not using a big enough container for your cannabis plant’s size, root binding is likely to happen. 

A big plant needs space for a healthy root system or will struggle with nutrient uptake and water absorption.

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Delayed repotting

When a plant stays in the same pot for too long, the roots eventually fill the entire container, becoming root bound. 

Repotting your cannabis plant before this happens can prevent a lot of issues down the line.

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Inadequate pot size for growing style

Depending on whether you’re growing indoors or outdoors and on your watering habits, the pot size should be suited to the growth you want to encourage.

Even if you use an automatic watering system to hydrate the plant multiple times daily, it may only delay the inevitable. 

Eventually, the plant will still become root bound if it doesn’t have enough space for the roots to grow.

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Root bound cannabis symptoms

How can you tell if a plant is root-bound? Spotting the signs early on can save you time and help your cannabis plants stay healthy. 

Here are some tell-tale signs of root bound cannabis:  

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Stunted growth

One of the first signs is slow or halted growth, as the plant can’t access enough nutrients to keep up with its size, leading to nutrient deficiency.   

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Drooping or yellowing leaves

Nutrient deficiency often results in discoloured or drooping leaves. If your cannabis plant’s leaves are turning yellow or curling, check for root binding as a possible cause. 

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Roots poking through holes in the pot

If you can see roots coming through the holes at the bottom of the pot, it’s a sure sign that your plant needs more room.

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Dense root ball

When removing the plant from its pot, you might notice the root system has become a solid mass, tangled together in a compact shape. 

This means the plant’s roots have no more space to spread out and are essentially competing with each other for nutrients.

By catching these signs early, you can take steps to fix the problem before it seriously impacts your plant’s health.

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Root bound vs pot bound?

While root bound and pot bound are sometimes used interchangeably, they have distinct meanings. 

A root-bound plant has outgrown its pot to the point where roots form a tight, circling mass, severely restricting growth. 

A pot-bound plant has filled its container but hasn’t yet developed the same level of root crowding. 

Pot-bound plants may still grow reasonably well but eventually become root bound without repotting. 

Spotting these differences early can guide you to repot or root prune as needed, ensuring your cannabis plants have enough room in their growing containers for optimal growth and nutrient uptake. 

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Effects of root bound cannabis on plant health

Once a cannabis plant becomes root bound, its growth above ground begins to suffer. Here are some effects to watch out for:

• Nutrient deficiencies: A root-bound plant will struggle to take up essential nutrients, often resulting in nutrient deficiencies. You might see signs like discolouration in the leaves or weak stems.
• Frequent watering needs: With limited root space, water and nutrients are quickly used up, meaning the soil dries out fast. You’ll find yourself watering and feeding the plant much more often. If left unaddressed, even frequent watering won’t be enough to sustain the plant.
• Poor root and shoot growth: A cramped root system prevents the plant from growing properly, which affects everything from foliage density to bud production.

In severe cases, a root-bound cannabis plant may stop growing altogether, limiting its potential and reducing yield.

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How to fix root-bound cannabis: Effective solutions

If you’ve discovered your cannabis plant is root-bound, don’t worry. There are some fairly easy and effective ways to remedy the situation and get it back on track. 

Here’s how to fix root bound plants, step by step:

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1. Repotting root bound cannabis plants

• Choose the right pot: Start by selecting a larger pot with adequate holes for drainage to prevent future root binding. Aim for a pot size that gives the roots plenty of growing space. 
• Prepare fresh potting mix: Fill the new container with fresh potting mix, which will give your cannabis plant access to more nutrients and better aeration. Make sure the growing medium, whether soil or another substrate, suits your setup.
• Remove the plant carefully: Gently remove the plant from its current pot. If the root ball is densely packed, be cautious to avoid damaging the roots as you lift it out.
• Loosen the roots: If the roots form a compact, tangled mass, gently tease them apart to encourage outward growth. In severe cases where the roots are tightly bound, you might need to prune or trim the root ball slightly to create space for new growth.

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2. Root pruning

• Root pruning is a technique that can help revitalise severely root-bound plants. Use a sharp, sterile knife to carefully trim away about an inch of the root ball’s outer layer, stimulating new root growth and preventing the roots from compacting.
• Pruning the roots can also help balance the plant’s growth above ground by reducing the competition for nutrients within the root system. After pruning, ensure the plant is potted in a suitable new container to give the roots ample space to spread.

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3. Repotting tips to ensure healthy growth

• When transplanting into a bigger pot, make sure the new pot isn’t excessively large, as this can lead to overwatering issues. Aim for a pot size slightly larger than the current one to allow a gradual increase in root space.
• If possible, use air pots or fabric pots. These types of containers allow air pruning, where roots naturally stop growing at the container’s edge, reducing the chance of root binding.
• After repotting, water the plant well to settle the new soil around the roots. Avoid adding fertiliser immediately after repotting, as the fresh potting mix will often have enough nutrition to sustain the plant for a few weeks. 

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Preventing root bound cannabis in the future

To avoid root binding issues in the future, consider these preventive measures:

1. Start with the right pot size: Selecting a container that’s appropriate for your cannabis plant’s final size can make a big difference. Small pots are fine for seedlings or early vegetative stages but be prepared to increase pot size as your plant grows.
2. Monitor your cannabis plant’s root system: Regularly check for signs that the roots are reaching the edge of the pot. You don’t have to repot every time, but it’s a good indicator of when a larger pot may be needed.
3. Choose containers that support healthy roots: Air pots and fabric pots are excellent options to prevent root circling. By allowing air to reach the root tips, they enable natural pruning and healthier roots overall.  
4. Repot early, not late: Proactively repotting when you see early signs of root binding will help your plant continue to grow properly without the stress of cramped roots.
5. Water and feed adequately: If you’re growing a large plant in a relatively small pot, it may need more frequent watering and feeding. An automatic watering system can help manage these needs, but remember that even frequent watering has limits if the plant is root bound.

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Takeaways

Dealing with root-bound cannabis can seem challenging, but with the right steps, it’s easy to fix and prevent in the future. 

By paying attention to pot size, keeping an eye on the roots, and repotting when necessary, you can ensure your cannabis plants have the best conditions to thrive. 

Remember, a healthy root system is key to achieving healthy growth and a bountiful yield, so don’t hesitate to make adjustments as your plants grow.

Happy growing!

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FAQs

How do I know if my cannabis plant is root bound?

If you’re seeing signs like stunted growth, yellowing leaves, or roots poking through holes in the bottom of the pot, these could be indicators of root binding. 

Lifting the plant out of its pot and observing a dense, compact root ball is a clear confirmation of a rootbound cannabis plant.

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What’s the best way to prevent root bound cannabis?

Starting with an appropriately sized container and checking the roots periodically can prevent rootbound cannabis plants. 

Using fabric or air pots can also help by supporting natural root pruning.

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How do you fix severely rootbound plants?

To fix a severely root bound weed plant, start by carefully removing it from its container. 

If the cannabis roots form a dense mass, use a sharp knife to trim away the outer layer of the root ball - about an inch deep. 

This process, known as root pruning, encourages fresh root growth and prevents future binding. 

Loosen the roots gently with your hands to promote outward growth. Then, repot the plant in a larger container with fresh substrate and ensure adequate drainage.  

Water thoroughly, allowing the plant to settle, and give it a few days to adjust to its new space.

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Can a root-bound plant be saved?

Yes, a rootbound cannabis plant can be saved with the right approach. 

Start by assessing the roots; if the plant’s roots are densely packed, it may need root pruning to revive growth.  

After trimming, repot the plant in a larger container with fresh soil, allowing enough space for roots to spread. 

Ensure the new pot has good drainage to prevent waterlogging. This will help the roots access oxygen and nutrients more efficiently. 

With proper care, including regular watering and nutrient support, previously rootbound cannabis plants can recover and continue growing vigorously, ultimately boosting yield and plant health.

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Can a rootbound cannabis plant recover fully?  

Yes! A root-bound plant can recover and continue growing well with prompt action, including repotting and root pruning if necessary. 

Repotting gives the root system the space it needs to absorb water and nutrients effectively, supporting healthy growth.

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What happens if you don't repot root bound plants?

If you don’t repot root bound plants, they will struggle to thrive.

As roots fill every inch of the container, they compete for water and nutrients, leading to nutrient deficiencies, stunted growth, and small buds. 

A marijuana plant root ball can become a dense mass, restricting airflow and causing the soil to dry out more quickly.  

Over time, a severely root bound plant will stop growing altogether, and issues like drooping or yellowing leaves become more pronounced. 

Without enough space in the container, roots cannot support healthy marijuana plant growth, and the plant may suffer long-term stress, reducing both yield and quality.

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Should I worry about root binding if I water my plant multiple times a day?

An auto-watering system can delay root binding issues, but it won’t prevent them entirely. 

Eventually, the plant will outgrow its container, even if watered frequently, so a larger pot will still be needed.

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