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How to Fix Root Bound Cannabis?

Added 14 November 2022

Did you know that the Burj Khalifa’s foundation pillars go 50 meters deep? Suppose they were half the size, they wouldn’t be able to hold the skyscraper up. Your cannabis plant’s roots function similarly.

When the roots grow, the plant grows, and bigger roots can sustain a bigger plant mass. But what happens if the roots run out of space? 

Root lock. 

This a common problem that many new growers face when growing cannabis. Learn all about root-bound cannabis in this article below.

What is a Root Bound Cannabis Plant?

What is a Root Bound Cannabis Plant?

Root-bound cannabis is a common problem for new cannabis growers and it occurs when the plant’s roots have outgrown the potting container and can no longer expand and develop. 

And this is a problem because cannabis roots need to expand and develop for healthy plant development and yield. When the roots become constrained by the container, they can’t absorb the nutrients and water properly, leading to malnutrition and nutrient deficiencies in the plant. Consequently, the plants become weak and eventually die. 

On the contrary, if your cannabis plant’s roots have enough space to grow and expand, the plant can develop a rich root system and uptake more nutrients, leading to vigorous growth and a better yield. 

In most cases, root-bound cannabis occurs in indoor grow rooms where the grower uses pots, but sometimes, it can also occur in outdoor gardens when the roots’ growth is restrained due to rocks or other foreign objects in the soil. 

How to Identify Root-Bound Cannabis?

How to Identify Root-Bound Cannabis?

You must learn how to identify root-bound cannabis because it can destroy your plant’s harvest if not treated on time. Fortunately, root-bound cannabis shows itself via various symptoms — some are easy to spot, others not. But here are the symptoms that you should look out for.

1. Symptoms of Nutrient Deficiencies

As roots’ development halts due to lack of space, the cannabis plant cannot uptake the nutrients necessary for nourishment. This leads to various nutrient deficiencies, including water deficiency. 

Some common symptoms of nutrient deficiencies include:

  • Yellow spots on the leaves that eventually turn brown
  • Curling of leaves
  • Wilting and dying of leaves 
  • Areas between the veins of older leaves start turning yellow
  • In some cases, the leaves also show rust-colored spots 
  • Weak or stunted growth of the plant 

If your plant only shows signs of a specific nutrient deficiency, it is likely, not due to the roots suffocating. However, if you spot signs of several nutrient deficiencies, it is wise to check for other signs of root-bound cannabis.

2. Nutrient Burn

On the contrary, you may also see symptoms of nutrient burn when the roots have outgrown the container. Nutrient burn is a result of over-fertilization and symptoms include:

This is because all the nutrients the plant is absorbing in the root zone are being directed to the plant and not to the roots since the roots can’t grow anymore.

3. Unhealthy Appearance of the Plant

If your cannabis plant does not look healthy, it is likely suffering from some condition. In this case, it could be a root lock. Here are some symptoms of unhealthy appearance caused by root lock:

  • Leaves losing their color
  • Stunted growth of the plant 
  • Formation of small buds 
  • Weak or flimsy plant branches and stems, etc. 

4. Soil Drying Out Too Quickly

Another common symptom of root-bound cannabis is the soil drying out quickly. This is because the roots are too big for the container and are not getting enough water supply when you water the plant. 

However, soil drying out too quickly can also be caused due to other reasons — wrong pH, nutrient issues, poor water quality, etc. — but if you are doing everything correctly and still experiencing this problem, it is likely due to root-bound cannabis. 

5. Stunted Growth of Buds or Small Buds 

When your cannabis plant experiences root lock, it cannot properly absorb vital nutrients required for healthy bud development, resulting in the buds growing smaller than usual. If you notice your plant’s buds have suddenly stopped growing or are growing slower than expected, you need to check for root lock. 

6. Plant Tipping Over 

Somewhat of a Looney Tunes logic, but if your plant constantly keeps tipping over under its own weight, you should check for root lock. In normal circumstances, the roots act to balance the plant’s center of gravity, but if the plant grows big and the roots don’t, the plant mass gets heavier than the roots can balance, leading to tipping over. 

Of course, this is a tricky symptom to identify because cannabis plants can tip over due to other reasons, including new growth, wind, uneven surface, or genetics. 

How to Fix Root Bound Cannabis?

How to Fix Root Bound Cannabis?

As long as you act quickly upon spotting root lock in your cannabis, you can save your plant and reverse the damage done quite easily. Follow these steps to fix the root lock in your cannabis plants.

1. De-pot the Plant 

The first step is to remove the plant from the pot since it has outgrown it. To easily depot your plant, place your hand on the soil, hold the stem with your other hand, tip the pot to one side and let gravity slide the plant out of the container. 

If the root lock is severe, you may have to massage the pot to loosen the soil. If this trick also fails, grab a long knife and slide the blade around the inner edge of the pot. In the worst-case scenario, you can break open the container, too. 

But be gentle so you don’t damage the roots of the plant. 

2. Loosen the Root Mass

Before you replant your cannabis, it is crucial to loosen the root ball because the roots may have locked themselves. So, with your fingers, gently untangle the roots and spread them out. This will not only break the root lock but also allow the roots to grow in the right direction. 

3. Consider Pruning the Roots

While you don’t want to damage the roots, you may have to prune them. So, use disinfected pruning scissors and prune the ends of the root. Doing so removes the dead ends, letting the roots recover and grow properly. 

When pruning, always use sharp scissors. Never use your fingers as it can cause unnecessary trauma to the roots. 

4. Transplant into a Bigger Container

Now, the final step. Once you have untangled the roots and pruned the dead ends, it’s time to move them into a bigger container. This is not a difficult step, but you should do it gently and safely so you don’t cause a shock to your plant. 

Follow these steps to repot your cannabis plant:

  • Put on some gloves so you don’t contaminate the roots
  • Spray some water on the plant to minimize the shock 
  • Prepare a container that’s at least twice the size of the previous container 
  • Fill the new container with soil while leaving some room for the plant 
  • Gently place the plant in the new container and cover the roots with soil 
  • Water the plant as usual 

Once you follow these steps, the symptoms of root lock will reverse and the plant will start growing correctly again. 

How to Prevent Root-Bound Cannabis?

How to Prevent Root-Bound Cannabis?

Fixing the root lock is easy, but preventing it is even easier. So, you should always try to prevent root-bound cannabis in the first place. Here are some ways you can avoid root lock in your cannabis plants:

  • Grow your cannabis plant in a pot that is big enough for the root system 
  • Transplant the plant into bigger pots at the right time 
  • Consider growing autoflowering cannabis plants only if you can manage a small container because many autoflowering strains don’t grow big and have smaller root mass

Remember, choosing the right container size is the best way to prevent root-bound cannabis.

How to Choose the Right Pot Size for Cannabis?

How to Choose the Right Pot Size for Cannabis?

When growing cannabis, you need to choose the right pot size from Day 1. This is because roots develop quickly during the early weeks of the plant’s growth. For most strains, a 5-gallon container works best. But for smaller strains, the size can go down to even 2 gallons, and for bigger strains, the size can go a couple of gallons up.

In any case, avoid planting your cannabis in containers that are too big. If the container is too big for the roots, the nutrients may fail to reach the roots properly, leading to nutrient deficiencies (again!), and you would have to compensate for this by adding more nutrients to the solution, which can lead to “hot” soil. 

Summary: How to Fix Root Bound Cannabis?

If you are a new grower and your plant is experiencing root lock, that’s alright. It is part of the learning process, but you must act quickly. Roots development is essential and proportional to the plant’s development and health.

Use the tips mentioned above to fix the root lock in your cannabis plant and take the correct measures to prevent it in the future. And choose the right container size and you won’t have to worry about root lock ever again.